fix broadcast on merge #62

[dgoo2308]

62 still did not fully work => the callback was not called

fixed with

@@ -589,7 +590,7 @@ bool Modbus::readRequest()
 bool Modbus::relevantAddress(uint8_t unitAddress)
 {
     // Every device should listen to broadcast messages.
-    if (isBroadcast())
+    if (unitAddress==MODBUS_BROADCAST_ADDRESS)
     {
         return true;
     }

secondly:

@@ -838,7 +839,7 @@ uint8_t Modbus::executeCallback(uint8_t slaveAddress, uint8_t callbackIndex, uin
         }
     }

-    return isBroadcast ? STATUS_ACKNOWLEDGE : STATUS_ILLEGAL_FUNCTION;
+    return isBroadcast ? STATUS_OK : STATUS_ILLEGAL_FUNCTION;
 }

 /**

for cleanup later and prevent acknowledge

[yaacov]

Thanks :green_heart: