patch 8.0.1655: outdated gdb message in terminal debugger unclear

Problem:    Outdated gdb message in terminal debugger unclear.
Solution:   Specifically mention the required gdb version.  Avoid getting
            stuck on pagination.

src/version.c

@@ -762,6 +762,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    1655,
 /**/
     1654,
 /**/