Add default server address.

app/src/main/res/layout/activity_main.xml

@@ -15,6 +15,7 @@
 		android:layout_margin="16dp"
 		android:hint="@string/server_address"
 		android:inputType="textUri"
+		android:text="@string/default_server_address"
 		tools:ignore="Autofill" />
 
 	<Button

app/src/main/res/values/strings.xml

@@ -2,6 +2,7 @@
 	<string name="app_name">Interferometer</string>
 
 	<string name="server_address">Server address</string>
+	<string name="default_server_address">139.162.237.194:40404</string>
 	<string name="server_address_error">Invalid address</string>
 	<string name="no_bluetooth_error">Device does not have Bluetooth</string>