patch 8.1.1299: "extends" from 'listchars' is used when 'list' is off

Problem:    "extends" from 'listchars' is used when 'list' is off. (Hiroyuki
            Yoshinaga)
Solution:   Only use the "extends" character when 'list' is on. (Hirohito
            Higashi, closes #4360)

src/version.c

@@ -767,6 +767,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    1299,
 /**/
     1298,
 /**/