Fixed bug in bulk importers

Previously when using one of the bulk importers within the app, it was possible to make changes to your Excel or CSV file, and then hit "Refresh" within Church Social to upload and validate the file again. Unfortunately, this behaviour was broken recently in Google Chrome as a result of a new security restriction they added.

We have fixed this issue by removing the "Refresh" option, and making it clear that you now need to reselect the import file from your device.

This update has been applied to the people importer, schedule importer, contribution importer, and library importer.