patch 8.2.2738: extending a list with itself can give wrong result

Problem:    Extending a list with itself can give wrong result.
Solution:   Remember the item before where the insertion happens and skip to
            after the already inserted items. (closes #1112)

src/version.c

@@ -750,6 +750,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    2738,
 /**/
     2737,
 /**/