rtc: Fix issue with CONFIG_REALTIME_ONLY

Issue was that update_gf_group_index was excluded
under the flag, which is needed.

Along with https://aomedia-review.googlesource.com/c/aom/+/91501,
this make the real-time coding bitexact with the
CONFIG_REALTIME_ONLY flag on/off.

Change-Id: I8e53c02eb154e6c90263fb473faa7b321f5344fb
diff --git a/av1/encoder/encode_strategy.c b/av1/encoder/encode_strategy.c
index a9ecbd3..ff6af67 100644
--- a/av1/encoder/encode_strategy.c
+++ b/av1/encoder/encode_strategy.c
@@ -173,7 +173,6 @@
   }
 }
 
-#if !CONFIG_REALTIME_ONLY
 static INLINE void update_gf_group_index(AV1_COMP *cpi) {
   // Increment the gf group index ready for the next frame. If this is
   // a show_existing_frame with a source other than altref, or if it is not
@@ -184,14 +183,11 @@
     ++cpi->gf_group.index;
   }
 }
-#endif
 
 static void update_rc_counts(AV1_COMP *cpi) {
   update_keyframe_counters(cpi);
   update_frames_till_gf_update(cpi);
-#if !CONFIG_REALTIME_ONLY
   update_gf_group_index(cpi);
-#endif
 }
 
 // Get update type of the current frame.