patch 8.1.1481: length for two-digit rgb termresponse is off by one

Problem:    Length for two-digit rgb termresponse is off by one.
Solution:   Adjust the length. (closes #4494)
diff --git a/src/version.c b/src/version.c
index 72f4009..2fd64c3 100644
--- a/src/version.c
+++ b/src/version.c
@@ -768,6 +768,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    1481,
+/**/
     1480,
 /**/
     1479,