[iOS] Avoid OpenGL driver whining on EAGLES2Context::destroyFramebuffer() when there are no any.
[iOS] Avoid OpenGL driver whining on EAGLES2Context::destroyFramebuffer() when there are no any.

OGRECave/ogre,paroj/ogre,OGRECave/ogre,paroj/ogre,paroj/ogre,OGRECave/ogre,paroj/ogre,OGRECave/ogre,OGRECave/ogre,paroj/ogre