client: render: fixed weird reflections distortion on non-axial mirro…

…r surfaces (fix #219)

Thanks to g-cont for figuring out :)

client/render/gl_subview.cpp

@@ -89,6 +89,7 @@ texFlags_t R_SetupMirrorView( msurface_t *surf, ref_viewpass_t *rvp, matrix4x4 &
 	rvp->viewangles[0] = anglemod( angles[0] );
 	rvp->viewangles[1] = anglemod( angles[1] );
 	rvp->viewangles[2] = anglemod( angles[2] );
+	rvp->viewangles[2] = -rvp->viewangles[2];
 	rvp->vieworigin = origin;
 
 	rvp->fov_x = RI->view.fov_x;