patch 8.1.1399: popup windows not adjusted when switching tabs

Problem:    Popup windows not adjusted when switching tabs.
Solution:   Save and restore first_tab_popupwin. Fix closing a tabpage.
diff --git a/src/version.c b/src/version.c
index 8cfb965..78a932e 100644
--- a/src/version.c
+++ b/src/version.c
@@ -768,6 +768,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    1399,
+/**/
     1398,
 /**/
     1397,