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)

src/version.c

@@ -775,6 +775,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    1055,
 /**/
     1054,
 /**/