rviz display: disable Query Start State by default

This property is "only" used by people playing around with planning internals,
e.g. the people maintaining the code..

The "average" user does not expect to be able to manipulate the start state of the motion-request
te makes from rviz - it doesn't make sense if you want to actually move the robot.
Therefore, disable the start-state by default to reduce the initial complexity
the average user is confronted with.

visualization/motion_planning_rviz_plugin/src/motion_planning_display.cpp

@@ -131,7 +131,7 @@ MotionPlanningDisplay::MotionPlanningDisplay() :
   show_workspace_property_ = new rviz::BoolProperty("Show Workspace", false, "Shows the axis-aligned bounding box for the workspace allowed for planning",
                                                     plan_category_,
                                                     SLOT(changedWorkspace()), this);
-  query_start_state_property_ = new rviz::BoolProperty("Query Start State", true, "Shows the start state for the motion planning query",
+  query_start_state_property_ = new rviz::BoolProperty("Query Start State", false, "Set a custom start state for the motion planning query",
                                                        plan_category_,
                                                        SLOT(changedQueryStartState()), this);
   query_goal_state_property_ = new rviz::BoolProperty("Query Goal State", true, "Shows the goal state for the motion planning query",