patch 9.0.0454: incorrect color for modeless selection with GTK

Problem:    Incorrect color for modeless selection with GTK.
Solution:   Use simple inversion instead of XOR. (closes #11111)
diff --git a/src/version.c b/src/version.c
index 9701d6d..9208d6a 100644
--- a/src/version.c
+++ b/src/version.c
@@ -704,6 +704,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    454,
+/**/
     453,
 /**/
     452,