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/term.c b/src/term.c
index 8d6a98e..afa622e 100644
--- a/src/term.c
+++ b/src/term.c
@@ -4990,7 +4990,7 @@
 			int is_4digit = i - j >= 21 && tp[j + 11] == '/'
 							  && tp[j + 16] == '/';
 
-			if (i - j >= 14 && STRNCMP(tp + j + 3, "rgb:", 4) == 0
+			if (i - j >= 15 && STRNCMP(tp + j + 3, "rgb:", 4) == 0
 			    && (is_4digit
 				   || (tp[j + 9] == '/' && tp[i + 12 == '/'])))
 			{
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,