[TD-225] free content while in-compatible client connect to taosd and send hb message.

src/mnode/src/mnodeShow.c

@@ -239,6 +239,7 @@ static int32_t mnodeProcessHeartBeatMsg(SMnodeMsg *pMsg) {
 
   SCMHeartBeatMsg *pHBMsg = pMsg->rpcMsg.pCont;
   if (taosCheckVersion(pHBMsg->clientVer, version, 3) != TSDB_CODE_SUCCESS) {
+    rpcFreeCont(pRsp);
     return TSDB_CODE_TSC_INVALID_VERSION;  // todo change the error code
   }