patch 8.1.1303: not possible to hide a balloon

Problem:    Not possible to hide a balloon.
Solution:   Hide the balloon when balloon_show() is called with an empty
            string or list.  Add balloon_gettext().
diff --git a/src/version.c b/src/version.c
index 96c72fa..8aef9dd 100644
--- a/src/version.c
+++ b/src/version.c
@@ -768,6 +768,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    1303,
+/**/
     1302,
 /**/
     1301,