windows opengl: Call InitGLEWDebugging() after we have the context.

Change-Id: I1582443cf6799dd73a3909660d524eaacbc2d909
Reviewed-on: https://gerrit.libreoffice.org/18237Reviewed-by: Miklos Vajna <vmiklos@collabora.co.uk>
Tested-by: Miklos Vajna <vmiklos@collabora.co.uk>

vcl/source/opengl/OpenGLContext.cxx

@@ -998,7 +998,6 @@ bool OpenGLContext::ImplInit()
     }
 
     wglMakeCurrent(NULL, NULL);
-    InitGLEWDebugging();
     wglDeleteContext(hTempRC);
 
     if (!wglMakeCurrent(m_aGLWin.hDC, m_aGLWin.hRC))
@@ -1008,6 +1007,8 @@ bool OpenGLContext::ImplInit()
         return false;
     }
 
+    InitGLEWDebugging();
+
     g_vShareList.push_back(m_aGLWin.hRC);
 
     RECT clientRect;