patch 8.1.1757: text added with appendbufline() isn't displayed

Problem:    Text added with appendbufline() to another buffer isn't displayed.
Solution:   Update topline. (partly by Christian Brabandt, closes #4718)

src/version.c

@@ -777,6 +777,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    1757,
 /**/
     1756,
 /**/