Folder-Maildir.savemessageflags(): Only parse file name if flags changed
Folder-Maildir.savemessageflags(): Only parse file name if flags changed

Rather than always parsing the filename, we only need to do so if the flags
have actually changed, otherwise we can keep the filename.

Signed-off-by: Sebastian Spaeth <98dcb2717ddae152d5b359c6ea97e4fe34a29d4c@SSpaeth.de>

frioux/offlineimap,frioux/offlineimap