fix typo in Petra, thanks niektb for noticing

git-svn-id: http://svn.wildfiregames.com/public/ps/trunk@15829 3db68df2-c116-0410-a063-a993310a9797
Fixes some bugs related to IME text input in SDL2, including a possible crash, refs #2041. Behavior seems reasonably consistent now on Windows and OS X

git-svn-id: http://svn.wildfiregames.com/public/ps/trunk@15830 3db68df2-c116-0410-a063-a993310a9797
Merge 'remotes/trunk'