patch 9.1.1123: popup hi groups not falling back to defaults

Problem:  Highlight groups PopupSelected/PopupNotification/
          MessageWindow are supposed to fall back to default highlight
          groups if they are not defined. However, once a colorscheme
          has defined them, switching to another colorscheme that
          doesn't do so will leave behind a cleared colorscheme, which
          causes the fallback to fail.

Solution: Set up default links to the relevant fallback highlight
          groups, which makes sure a `:hi clear` command will reset the
          state properly (Yee Cheng Chin).

closes: #16676

Signed-off-by: Yee Cheng Chin <ychin.git@gmail.com>
Signed-off-by: Christian Brabandt <cb@256bit.org>
diff --git a/src/version.c b/src/version.c
index f400ca9..0e7e236 100644
--- a/src/version.c
+++ b/src/version.c
@@ -705,6 +705,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    1123,
+/**/
     1122,
 /**/
     1121,