hw: keep serial disabled with the sonoff rfbridge

ref. #2423

code/espurna/config/hardware.h

@@ -813,11 +813,12 @@
     #define RFB_PROVIDER        RFB_PROVIDER_EFM8BB1
     #endif
 
-    #if RFB_PROVIDER == RFB_PROVIDER_EFM8BB1
-    #define SERIAL_BAUDRATE         19200
+    #ifndef DEBUG_SERIAL_SUPPORT
     #define DEBUG_SERIAL_SUPPORT    0
     #endif
 
+    #define SERIAL_BAUDRATE         19200
+
     // Only used when RFB_PROVIDER is RCSWITCH
     #define RFB_RX_PIN          4
     #define RFB_TX_PIN          5