patch 8.1.1055: CTRL-G U in Insert mode doesn't work for shift-Left

Problem:    CTRL-G U in Insert mode doesn't work to avoid splitting the undo
            sequence for shift-left and shift-right.
Solution:   Also check dont_sync_undo for shifted cursor keys. (Christian
            Brabandt)
diff --git a/src/version.c b/src/version.c
index ba14981..e4e9279 100644
--- a/src/version.c
+++ b/src/version.c
@@ -776,6 +776,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    1055,
+/**/
     1054,
 /**/
     1053,