patch 8.1.1773: the preview popup window may be too far to the right

Problem:    The preview popup window may be too far to the right.
Solution:   Keep it inside the screen.  Also keep the close button and
            scrollbar visible if possible.

src/version.c

@@ -777,6 +777,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    1773,
 /**/
     1772,
 /**/