Translations: Handle "." in project name

This handles repositories like "oslo.utils". We cannot just remove
everything after the last ".", we need to be explicit and remove the
final ".git".

It fixes multiple occurences of oslo.utils for proposing translations:
https://review.openstack.org/#/q/status:open++branch:master+topic:transifex/translations,n,z

Change-Id: Iee4747eba75e87f5dc3cae696fafc8e7f563bd98
Merge "Translations: Handle "." in project name"