patch 8.2.2278: falling back to old regexp engine can some patterns

Problem:    Falling back to old regexp engine can some patterns.
Solution:   Do not fall back once [[:lower:]] or [[:upper:]] is used.
            (Christian Brabandt, closes #7572)

src/version.c

@@ -750,6 +750,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    2278,
 /**/
     2277,
 /**/