MOSCOW, July 23 (Reuters) - Residents of Moscow who sign up to fight in Ukraine will receive a down payment of 1.9 million roubles ($21,777) from the city, taking their annual pay in their first service year to 5.2 million roubles ($59,600), the mayor's office said on Tuesday. Total pay will include the downpayment, wages from the defence ministry, as well as regional and federal handouts, the office of Moscow Mayor Sergei Sobyanin said in a statement. The new payments will enter into force immediately, it said. The increase means that annual pay for Russian contract soldiers from Moscow will...