Comment 10 for bug 1565685

According to https://www.opengl.org/wiki/GLAPI/glGetString, glGetString() may return a null pointer if an error is generated, and still according to the documentation, that error could only be GL_INVALID_ENUM, which implies that GL_SHADING_LANGUAGE_VERSION is not an accepted value for the GL driver used in the emulator. Adding a guard in oxide to recover from such an error and avoid the crash might help, but it’s not clear to me why the driver thinks GL_SHADING_LANGUAGE_VERSION is not a valid query.