Add net package prefix to import order prefs

Thanks to Brian Northan for noticing its absence:
imagej/imagej-ops@8b3727c#commitcomment-13376613

config/eclipse-preferences.epf

@@ -31,7 +31,7 @@ file_export_version=3.0
 /instance/org.eclipse.jdt.ui/cleanup.qualify_static_field_accesses_with_declaring_class=false
 /instance/org.eclipse.jdt.core/org.eclipse.jdt.core.compiler.problem.enumIdentifier=error
 /instance/org.eclipse.jdt.ui/org.eclipse.jdt.ui.cleanupprofiles=<?xml version\="1.0" encoding\="UTF-8" standalone\="no"?>\n<profiles version\="2">\n<profile kind\="CleanUpProfile" name\="ImageJ" version\="2">\n<setting id\="cleanup.remove_unused_private_fields" value\="true"/>\n<setting id\="cleanup.always_use_parentheses_in_expressions" value\="false"/>\n<setting id\="cleanup.never_use_blocks" value\="false"/>\n<setting id\="cleanup.add_missing_deprecated_annotations" value\="true"/>\n<setting id\="cleanup.remove_unused_private_methods" value\="true"/>\n<setting id\="cleanup.convert_to_enhanced_for_loop" value\="false"/>\n<setting id\="cleanup.remove_unnecessary_nls_tags" value\="true"/>\n<setting id\="cleanup.sort_members" value\="false"/>\n<setting id\="cleanup.remove_unused_local_variables" value\="false"/>\n<setting id\="cleanup.remove_unused_private_members" value\="false"/>\n<setting id\="cleanup.never_use_parentheses_in_expressions" value\="true"/>\n<setting id\="cleanup.remove_unnecessary_casts" value\="true"/>\n<setting id\="cleanup.make_parameters_final" value\="true"/>\n<setting id\="cleanup.use_this_for_non_static_field_access" value\="false"/>\n<setting id\="cleanup.use_blocks" value\="false"/>\n<setting id\="cleanup.remove_private_constructors" value\="true"/>\n<setting id\="cleanup.always_use_this_for_non_static_method_access" value\="false"/>\n<setting id\="cleanup.remove_trailing_whitespaces_all" value\="true"/>\n<setting id\="cleanup.always_use_this_for_non_static_field_access" value\="false"/>\n<setting id\="cleanup.use_this_for_non_static_field_access_only_if_necessary" value\="true"/>\n<setting id\="cleanup.add_default_serial_version_id" value\="true"/>\n<setting id\="cleanup.make_type_abstract_if_missing_method" value\="false"/>\n<setting id\="cleanup.qualify_static_member_accesses_through_subtypes_with_declaring_class" value\="true"/>\n<setting id\="cleanup.make_variable_declarations_final" value\="true"/>\n<setting id\="cleanup.add_missing_nls_tags" value\="false"/>\n<setting id\="cleanup.format_source_code" value\="true"/>\n<setting id\="cleanup.add_missing_override_annotations" value\="true"/>\n<setting id\="cleanup.qualify_static_method_accesses_with_declaring_class" value\="false"/>\n<setting id\="cleanup.remove_unused_private_types" value\="true"/>\n<setting id\="cleanup.make_local_variable_final" value\="true"/>\n<setting id\="cleanup.add_missing_methods" value\="false"/>\n<setting id\="cleanup.add_missing_override_annotations_interface_methods" value\="true"/>\n<setting id\="cleanup.correct_indentation" value\="false"/>\n<setting id\="cleanup.remove_unused_imports" value\="true"/>\n<setting id\="cleanup.remove_trailing_whitespaces_ignore_empty" value\="false"/>\n<setting id\="cleanup.make_private_fields_final" value\="true"/>\n<setting id\="cleanup.add_generated_serial_version_id" value\="false"/>\n<setting id\="cleanup.organize_imports" value\="true"/>\n<setting id\="cleanup.sort_members_all" value\="false"/>\n<setting id\="cleanup.remove_trailing_whitespaces" value\="true"/>\n<setting id\="cleanup.use_blocks_only_for_return_and_throw" value\="false"/>\n<setting id\="cleanup.use_parentheses_in_expressions" value\="false"/>\n<setting id\="cleanup.add_missing_annotations" value\="true"/>\n<setting id\="cleanup.qualify_static_field_accesses_with_declaring_class" value\="false"/>\n<setting id\="cleanup.use_this_for_non_static_method_access_only_if_necessary" value\="true"/>\n<setting id\="cleanup.use_this_for_non_static_method_access" value\="false"/>\n<setting id\="cleanup.qualify_static_member_accesses_through_instances_with_declaring_class" value\="true"/>\n<setting id\="cleanup.add_serial_version_id" value\="false"/>\n<setting id\="cleanup.always_use_blocks" value\="true"/>\n<setting id\="cleanup.qualify_static_member_accesses_with_declaring_class" value\="true"/>\n<setting id\="cleanup.format_source_code_changes_only" value\="false"/>\n</profile>\n</profiles>\n
-/instance/org.eclipse.jdt.ui/org.eclipse.jdt.ui.importorder=com;java;javax;org;
+/instance/org.eclipse.jdt.ui/org.eclipse.jdt.ui.importorder=com;java;javax;net;org;
 /instance/org.eclipse.jdt.ui/cleanup_profile=_ImageJ
 /instance/org.eclipse.jdt.ui/cleanup.qualify_static_member_accesses_with_declaring_class=true
 /instance/org.eclipse.jdt.core/org.eclipse.jdt.core.compiler.problem.redundantSuperinterface=warning