Fix T59773: Raise exception if the gpu module is used in backgound mode.

Instead of crashing, an error message is displayed if a function of the gpu module is called without a GPU context.

Reviewers: brecht, campbellbarton, JacquesLucke, mont29

Subscribers: abdelmatinboulbayam, amir.shehata

Differential Revision: https://developer.blender.org/D4143

source/blender/python/gpu/gpu_py_api.h

@@ -1,30 +0,0 @@
-/*
- * ***** BEGIN GPL LICENSE BLOCK *****
- *
- * This program is free software; you can redistribute it and/or
- * modify it under the terms of the GNU General Public License
- * as published by the Free Software Foundation; either version 2
- * of the License, or (at your option) any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program; if not, write to the Free Software Foundation,
- * Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
- *
- * ***** END GPL LICENSE BLOCK *****
- */
-
-/** \file blender/python/gpu/gpu_py_api.h
- *  \ingroup bpygpu
- */
-
-#ifndef __GPU_PY_API_H__
-#define __GPU_PY_API_H__
-
-PyObject *BPyInit_gpu(void);
-
-#endif  /* __GPU_PY_API_H__ */