patch 8.1.1459: popup window border looks bad when 'ambiwidth' is "double"

Problem:    Popup window border looks bad when 'ambiwidth' is "double".
            (Yasuhiro Matsumoto)
Solution:   Only use line drawing characters when 'ambiwidth' is "single".
            (Ken Takata, closes #4477)
diff --git a/src/version.c b/src/version.c
index 53a2644..accea72 100644
--- a/src/version.c
+++ b/src/version.c
@@ -768,6 +768,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    1459,
+/**/
     1458,
 /**/
     1457,