patch 8.1.1819: :pedit does not work with a popup preview window

Problem:    :pedit does not work with a popup preview window.
Solution:   Avoid aborting with an error. (fixes #4777)  Also double check
            that after prepare_tagpreview() the current window is not a
            popup window.
diff --git a/src/version.c b/src/version.c
index 8537df1..76bb414 100644
--- a/src/version.c
+++ b/src/version.c
@@ -774,6 +774,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    1819,
+/**/
     1818,
 /**/
     1817,