git: update to v2.16.0

Update to git version v2.16.0:

* refs: convert resolve_ref_unsafe to struct object_id
  (49e61479be913f67e66bb3fdf8de9475c41b58bd)
* diff: remove DIFF_OPT_SET macro
  (23dcf77f48feb49c54bad09210f093a799816334)
* log: add option to choose which refs to decorate
  (65516f586b69307f977cd67cc45513a296cabc25)
* diff: convert flags to be stored in bitfields
  (02f2f56bc377c287c411947d0e1482aac888f8db)

Signed-off-by: Christian Hesse <mail@eworm.de>
diff --git a/ui-commit.c b/ui-commit.c
index 586fea0..abf58f6 100644
--- a/ui-commit.c
+++ b/ui-commit.c
@@ -41,7 +41,7 @@
 
 	format_display_notes(&oid, &notes, PAGE_ENCODING, 0);
 
-	load_ref_decorations(DECORATE_FULL_REFS);
+	load_ref_decorations(NULL, DECORATE_FULL_REFS);
 
 	cgit_print_layout_start();
 	cgit_print_diff_ctrls();