don't let phones send down fatally invalid RadioConfig records

and if a phone did in the past, fixup the garbage we saved in flash

src/MeshService.cpp

@@ -217,6 +217,7 @@ void MeshService::loop()
 void MeshService::reloadConfig()
 {
     // If we can successfully set this radio to these settings, save them to disk
+    nodeDB.resetRadioConfig(); // Don't let the phone send us fatally bad settings
     radio.reloadConfig();
     nodeDB.saveToDisk();
 }