patch 8.1.1444: not using double line characters for popup border

Problem:    Not using double line characters for popup border.
Solution:   Use double line characters if using utf-8.
diff --git a/src/version.c b/src/version.c
index 51dcae8..a82e6e9 100644
--- a/src/version.c
+++ b/src/version.c
@@ -768,6 +768,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    1444,
+/**/
     1443,
 /**/
     1442,