patch 8.0.1540: popup menu positioning fails with longer string

Problem:    Popup menu positioning fails with longer string.
Solution:   Only align with right side of window when width is less than
            'pumwidth' (closes #2661)
diff --git a/src/version.c b/src/version.c
index c75d290..48c21fc 100644
--- a/src/version.c
+++ b/src/version.c
@@ -779,6 +779,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    1540,
+/**/
     1539,
 /**/
     1538,