Disable refinements for skip mode when opfl_refine_type is REFINE_ALL

Fixes #442

av1/common/av1_common_int.h

diff --git a/av1/common/av1_common_int.h b/av1/common/av1_common_int.h
index 99c930d..4995130 100644
--- a/av1/common/av1_common_int.h
+++ b/av1/common/av1_common_int.h
@@ -4235,6 +4235,10 @@
                                              const MACROBLOCKD *xd,
 #endif  // CONFIG_COMPOUND_4XN
                                              const MB_MODE_INFO *mbmi) {
+#if CONFIG_SKIP_MODE_NO_REFINEMENTS
+  if (mbmi->skip_mode) return 0;
+#endif  // CONFIG_SKIP_MODE_NO_REFINEMENTS
+
   if (!opfl_allowed_for_cur_refs(cm,
 #if CONFIG_COMPOUND_4XN
                                  xd,