python: rename a header for further additions.

src/python/magnum/PyGL.h

@@ -1,3 +1,5 @@
+#ifndef magnum_PyGL_h
+#define magnum_PyGL_h
 /*
     This file is part of Magnum.
 
@@ -40,3 +42,5 @@ struct PyMesh: GL::Mesh {
 };
 
 }
+
+#endif

src/python/magnum/gl.cpp

@@ -39,7 +39,7 @@
 #include "corrade/EnumOperators.h"
 #include "magnum/bootstrap.h"
 #include "magnum/NonDestructible.h"
-#include "magnum/PyMesh.h"
+#include "magnum/PyGL.h"
 
 namespace magnum {
 

src/python/magnum/meshtools.cpp

@@ -30,7 +30,7 @@
 #include <Magnum/Trade/MeshData3D.h>
 
 #include "magnum/bootstrap.h"
-#include "magnum/PyMesh.h"
+#include "magnum/PyGL.h"
 
 namespace magnum {