Don't raise exception on early connection failure

sjrpc/core/rpcconnection.py

@@ -449,7 +449,12 @@ class RpcConnection(object):
 
         # Close the connection socket:
         try:
-            self._sock.shutdown(socket.SHUT_RDWR)
+            try:
+                self._sock.shutdown(socket.SHUT_RDWR)
+            except socket.error as e:
+                if e.errno != errno.ENOTCONN:
+                    raise
+
             self._sock.close()
         except socket.error as err:
             #self.logger.warn('Error while socket close: %s', err)