patch 8.1.1631: displaying signs is inefficient

Problem:    Displaying signs is inefficient.
Solution:   Avoid making multiple calls to get information about a placed
            sign. (Yegappan Lakshmanan, closes #4586)

src/version.c

@@ -777,6 +777,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    1631,
 /**/
     1630,
 /**/