Updated FindMagnum.cmake from Magnum repository.
Updated FindMagnum.cmake from Magnum repository.

mosra/magnum-examples,mosra/magnum-examples,mosra/magnum-examples,Squareys/magnum-examples,Squareys/magnum-examples,Squareys/magnum-examples,Squareys/magnum-examples,mosra/magnum-examples,mosra/magnum-examples,mosra/magnum-examples,mosra/magnum-examples