[FIX] forums: Use modifier avarize as tiki-show_user_avatar.php is buggy and doesn't support static avatars

git-svn-id: file:///var/local/code.tiki.org/tikisvn/branches/13.x@52741 b456876b-0849-0410-b77d-98878d47e9d5
[FIX] forums: Use modifier avarize as tiki-show_user_avatar.php is buggy and doesn't support static avatars (missed some)

git-svn-id: file:///var/local/code.tiki.org/tikisvn/branches/13.x@52742 b456876b-0849-0410-b77d-98878d47e9d5