Update reels_test4 reference following fix to subtitle reel numbering.

diff --git a/test/data b/test/data
index 789bd241695300320126152037ae171ec6581466..83a0643c345454864dafabfb9d4703db30dd0bc0 160000 (submodule)
--- a/test/data
+++ b/test/data
@@ -1 +1 @@
-Subproject commit 789bd241695300320126152037ae171ec6581466
+Subproject commit 83a0643c345454864dafabfb9d4703db30dd0bc0