Correctly unset currentUsedSize when cancelAll and when the file has reached the max total size per post
Correctly unset currentUsedSize when cancelAll and when the file has reached the max total size per post

Signed-off-by: Jessica González <52329a27ea5670aeec0efeeb0773bf1b4f1affa1@missallsunday.com>

StealthWombat/SMF2.1-more-forkery,StealthWombat/SMF2.1-more-forkery