patch 7.4.2220

Problem:    printf() gives an error when the argument for %s is not a string.
            (Ozaki Kiichi)
Solution:   Behave like invoking string() on the argument. (Ken Takata)

src/version.c

@@ -763,6 +763,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    2220,
 /**/
     2219,
 /**/