Otherwise materials like EMT_TRANSPARENT_ALPHA_CHANNEL no longer worked.
Not sure if this is now causing other problems, but it no longer seems to break the known cases (tests about that pass again). If there are new problems we need new tests to show 'em.

git-svn-id: svn://svn.code.sf.net/p/irrlicht/code/trunk@5086 dfc29bdd-3216-0410-991c-e03cc46cb475