patch 8.1.1315: there is always a delay if a termrequest is never answered

Problem:    There is always a delay if a termrequest is never answered.
Solution:   When the response is not received within two seconds consider the
            request to have failed.

src/version.c

@@ -767,6 +767,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    1315,
 /**/
     1314,
 /**/