Update ipsw-patch/ibootim.c

Removed deprecated libpng struct errors. It will now build on the latest libpng.
Update ipsw-patch/ibootim.c

Removed deprecated libpng struct errors. It will now build on the latest libpng.
Merge branch 'master' of https://github.com/squiffy/xpwn
Merge pull request #1 from squiffy/master

ibootim.c wont build on latest libpng.