Main: Texture - fix off by one in num mipmaps in convertToImage (#2519)
Main: Texture - fix off by one in num mipmaps in convertToImage (#2519)

Signed-off-by: Kenji Brameld <07c09d5cb417177de45be426d5e46c6b9cffb88e@gmail.com>
OGRECave/ogre,paroj/ogre,paroj/ogre,OGRECave/ogre,paroj/ogre,paroj/ogre,OGRECave/ogre,OGRECave/ogre,OGRECave/ogre,paroj/ogre