[DISC] Fix device name discovery (#2093)

Fix issue introduced by #1936

Co-authored-by: Florian <1technophile@users.noreply.github.com>

main/ZgatewayBT.ino

@@ -939,7 +939,7 @@ void launchBTDiscovery(bool overrideDiscovery) {
         Log.trace(F("properties: %s" CR), properties.c_str());
         std::string brand = decoder.getTheengAttribute(p->sensorModel_id, "brand");
         std::string model = decoder.getTheengAttribute(p->sensorModel_id, "model");
-#    ifdef ForceDeviceName
+#    if ForceDeviceName
         if (p->name[0] != '\0') {
           model = p->name;
         }