patch 8.1.1447: not allowed to create an empty popup

Problem:    Not allowed to create an empty popup.
Solution:   Remove restriction that there is some text. (closes #4470)
diff --git a/src/version.c b/src/version.c
index 597fb90..9f316c1 100644
--- a/src/version.c
+++ b/src/version.c
@@ -768,6 +768,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    1447,
+/**/
     1446,
 /**/
     1445,