fix bluetooth prefs

res/values/arrays.xml

@@ -5,6 +5,7 @@
 		<item>@string/p_conn_udp</item>
 		<item>@string/p_conn_http</item>
 		<item>@string/p_conn_afsk</item>
+		<item>@string/p_conn_bt</item>
 	</string-array>
 	<string-array name="p_conntype_ev">
 		<item>tcp</item>

src/backend/Backend.scala

@@ -23,7 +23,7 @@ object Backend {
 			(s, p) => new TcpUploader(s, p),
 			R.xml.pref_tcp,
 			PASSCODE_OPTIONAL),
-		"bt" -> new BackendInfo(
+		"bluetooth" -> new BackendInfo(
 			(s, p) => new BluetoothTnc(s, p),
 			R.xml.pref_bluetooth,
 			PASSCODE_NONE)