detect if we misconfigure and try to connect to a mongos as if it were a config server.

this wasn't being caught on the single cofnig server case.  now detected but message
is rather cryptic:

caught exception in mongos main:
13106 nextSafe(): { $err: "unrecognized command: dbhash", code: 13390 }

1 files changed, 3 insertions, 3 deletions

diff --git a/s/config.cpp b/s/config.cpp
index c1410c9e33f..86b169afe40 100644
--- a/s/config.cpp
+++ b/s/config.cpp
@@ -456,9 +456,6 @@ namespace mongo {
     }
 
     bool ConfigServer::checkConfigServersConsistent( string& errmsg , int tries ) const {
-        if ( _config.size() == 1 )
-            return true;
-
         if ( tries <= 0 )
             return false;
 
@@ -485,6 +482,9 @@ namespace mongo {
             res.push_back(x);
         }
 
+        if ( _config.size() == 1 )
+            return true;
+
         if ( up == 0 ) {
             errmsg = "no config servers reachable";
             return false;