[BUG] update information and default value for Backup option

[dizzzz]

Since somewhere in the Java7 era, Java supports ZIP64 meaning that this limitation is not true anymore.

I'd like to request

• please remove the statement "(Don't use for database with more than 4gb)"
• to actually help users, please have the checkbox 'on' by default, so by default ZIP files are created

I am convinced that having even large ZIP files is in the interest of our end-user

reference:

• https://stackoverflow.com/questions/6738773/zip-files-with-java-is-there-a-limit

[dizzzz]

I have no idea how/where to change this myself, please could one help me here?

[joewiz]

For setting checkbox's default state, with paper-checkbox, see https://www.webcomponents.org/element/@polymer/paper-checkbox.