Change Profile->getUser() to match the current user

Change Profile->getUser() to match the current user

Profile->getUser() gets the User independently from common_current_user.
This means that changes to one does not affect the other, even if they
are the same user.
This changes that, so that getUser() returns common_current_user() if
they are both the same user.

This is done to fix a bug in the user profile settings, where changes in
the language and timezone are applied to the return value of
Profile->getUser() but not propagated to common_cur_user(), which causes
the profile settings to display incorrect information until the page is
refreshed.