patch 8.2.1514: multibyte vertical separator is cleared when dragging popup

Problem:    Multibyte vertical separator is cleared when dragging a popup
            window using a multi-byte character for the border.
Solution:   Only clear the character before the window if it is double width.
            (closes #6766)

src/version.c

@@ -754,6 +754,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    1514,
 /**/
     1513,
 /**/