fix #954, write selflowtemp with same value

src/devices/boiler.cpp

@@ -1711,7 +1711,9 @@ bool Boiler::set_flow_temp(const char * value, const int8_t id) {
     }
 
     //  no write/verify if there is no change, see https://github.com/emsesp/EMS-ESP32/issues/654
+    // put it to end of tx-queue
     if (v == selFlowTemp_) {
+        EMSESP::txservice_.add(Telegram::Operation::TX_WRITE, device_id(), EMS_TYPE_UBASetPoints, 0, (uint8_t *) &v, 1, 0, false);
         return true;
     }