Memory leak when disposing of the RdpControl.
Memory leak when disposing of the RdpControl.

The rdpControl was set to null too soon and by the time the timer ticked it had
no chance to be disposed of at all. Also, the timer itself was not disposed of.

Signed-off-by: Konstantina Chremmou <a7d1f757a659045fb6db8c1e3849a1c8ad00b97a@citrix.com>

kc284/xenadmin,xenserver/xenadmin,kc284/xenadmin,kc284/xenadmin,kc284/xenadmin,xenserver/xenadmin,xenserver/xenadmin,kc284/xenadmin