feat: add `ignore_mqtt` to LoRa config

ref.: https://github.com/meshtastic/firmware/pull/3117

app/src/main/java/com/geeksville/mesh/ui/components/config/LoRaConfigItemList.kt

@@ -181,6 +181,14 @@ fun LoRaConfigItemList(
                 onValueChanged = { loraInput = loraInput.copy { overrideFrequency = it } })
         }
 
+        item {
+            SwitchPreference(title = "Ignore MQTT",
+                checked = loraInput.ignoreMqtt,
+                enabled = enabled,
+                onCheckedChange = { loraInput = loraInput.copy { ignoreMqtt = it } })
+        }
+        item { Divider() }
+
         item {
             PreferenceFooter(
                 enabled = loraInput != loraConfig,