transmission: Add rpc_host_whitelist support.

It was requested as it can be useful under certain circumstances.

Disabled rpc_whitelist by default. Not only is there a firewall, but it denies access when IP address of the device is changed.

Added group support in UCI. Fixes cases where group does not match the user (nobody:nogroup).

Signed-off-by: Rosen Penev <rosenp@gmail.com>

net/transmission/files/transmission.config

@@ -3,6 +3,7 @@ config transmission
 	option config_dir '/tmp/transmission'
 	option config_overwrite '1'
 	option user 'transmission'
+	option group 'transmission'
 	option mem_percentage 50
 	option nice 10
 	option alt_speed_down 50
@@ -49,13 +50,14 @@ config transmission
 	option rpc_authentication_required false
 	option rpc_bind_address '0.0.0.0'
 	option rpc_enabled true
+	option rpc_host_whitelist '127.0.0.1,192.168.1.*'
 	option rpc_host_whitelist_enabled false
 	option rpc_password ''
 	option rpc_port 9091
 	option rpc_url '/transmission/'
 	option rpc_username ''
 	option rpc_whitelist '127.0.0.1,192.168.1.*'
-	option rpc_whitelist_enabled true
+	option rpc_whitelist_enabled false
 	option scrape_paused_torrents_enabled true
 	option script_torrent_done_enabled false
 	option script_torrent_done_filename ''