patch 8.1.1799: cannot avoid mapping for a popup window

Problem:    Cannot avoid mapping for a popup window.
Solution:   Add the "mapping" property, default TRUE.
diff --git a/src/version.c b/src/version.c
index ec67fe4..b2c4416 100644
--- a/src/version.c
+++ b/src/version.c
@@ -774,6 +774,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    1799,
+/**/
     1798,
 /**/
     1797,