Fixed infinite loop if glError persists.

src/ACGL/OpenGL/Debug.cc

@@ -79,7 +79,8 @@ void APIENTRY ACGL_KHR_default_debug_callback( GLenum _source, GLenum _type, GLu
 
 
     // delete all errors to not create another error log for the same problem:
-    while ( glGetError() != GL_NO_ERROR ) {}
+	int tries(100);
+    while ( glGetError() != GL_NO_ERROR && --tries > 0 ) {}
 }
 
 } // OpenGL