patch 8.1.1464: only 4-digit rgb termresponse is recognized

Problem:    Only 4-digit rgb termresponse is recognized.
Solution:   Also recognize 2-digit rgb response. (closes #4486)
diff --git a/src/version.c b/src/version.c
index 7d86aae..57f6db3 100644
--- a/src/version.c
+++ b/src/version.c
@@ -768,6 +768,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    1464,
+/**/
     1463,
 /**/
     1462,