MXS-2140: Fix readwritesplit configuration processing

Runtime configuration changes did not properly enable implicitly enabled
parameters.

server/modules/routing/readwritesplit/readwritesplit.cc

@@ -228,28 +228,6 @@ RWSplit* RWSplit::create(SERVICE* service, MXS_CONFIG_PARAMETER* params)
         return NULL;
     }
 
-    /** These options cancel each other out */
-    if (config.disable_sescmd_history && config.max_sescmd_history > 0)
-    {
-        config.max_sescmd_history = 0;
-    }
-
-    if (config.optimistic_trx)
-    {
-        // Optimistic transaction routing requires transaction replay
-        config.transaction_replay = true;
-    }
-
-    if (config.transaction_replay)
-    {
-        /**
-         * Replaying transactions requires that we are able to do delayed query
-         * retries and reconnect to a master.
-         */
-        config.delayed_retry = true;
-        config.master_reconnection = true;
-    }
-
     return new(std::nothrow) RWSplit(service, config);
 }