Set refresh_lst_frame to 0 for GF_UPDATE frame

No coding stats changed.

Change-Id: Idb51e083bb51e0c67f19bad2a8f089d4bd94ef05
diff --git a/av1/encoder/encode_strategy.c b/av1/encoder/encode_strategy.c
index 6f686a4..3203e9a 100644
--- a/av1/encoder/encode_strategy.c
+++ b/av1/encoder/encode_strategy.c
@@ -61,9 +61,7 @@
       break;
 
     case GF_UPDATE:
-      // TODO(zoeliu): To further investigate whether 'refresh_last_frame' is
-      //               needed.
-      frame_params->refresh_last_frame = 1;
+      frame_params->refresh_last_frame = 0;
       frame_params->refresh_golden_frame = 1;
       frame_params->refresh_bwd_ref_frame = 0;
       frame_params->refresh_alt_ref_frame = 0;