patch 8.2.1517: cannot easily get the character under the cursor

Problem:    Cannot easily get the character under the cursor.
Solution:   Add the {chars} argument to strpart().

src/version.c

@@ -754,6 +754,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    1517,
 /**/
     1516,
 /**/