home location not updating in survey grid

#### Issue details
when you move the home to create a survey grid home location doesn't update in the grid creation dialog, to be able to update it you have to restart mission planner

#### Version
1.3.71 build 1.3.7451.16917

Start by reproducing the issue in Mission Planner 1.3.71, moving the home location and opening the survey grid creation dialog. Trace the dialog's home-location display and refresh behavior. Done means the dialog reflects the newly moved home location without restarting Mission Planner.

Written by the indexing model from the issue text.