use ems/ems+ telegrams for forceheatingoff, add fanspd #2702

src/devices/boiler.h

@@ -245,6 +245,7 @@ class Boiler : public EMSdevice {
     uint8_t  hpPumpMode_;
     uint8_t  hpSetDiffPress_;
     uint8_t  fan_;
+    uint8_t  fanspd_;
     uint8_t  hpshutdown_;
     uint8_t receiverValveVr0_;
     uint8_t expansionValveVr1_;