MXS-1593: Don't display stale status

As the stale status is not a real status bit and it's used to retain the
history of a master, there is no need to print it in any output. This
output will only confuse users now that the stale status will not be
cleared from masters that go down.

server/core/server.cc

@@ -706,10 +706,6 @@ server_status(const SERVER *server)
     {
         strcat(status, "Slave of External Server, ");
     }
-    if (server_status & SERVER_STALE_STATUS)
-    {
-        strcat(status, "Stale Status, ");
-    }
     if (server_status & SERVER_MASTER_STICKINESS)
     {
         strcat(status, "Master Stickiness, ");