Disconnected client are removed from server's array

When client disconnects server must remove it from it's array.
Else other clients are wrongly informed that disconnected client is connected
and when she connects again messages are not delivered to her.
Updated indentation in server according to Android code style

See http://source.android.com/source/code-style.html#use-spaces-for-indentation
One difference - lines doesn't exceed 80 columns.