Fix for destroying gatt client in case of error.

Fix for destroying gatt client in case of error.

Client Handle was not destroyed.
Because of that from second time onwards client handle was not getting created.
MTU size was set to default and bt buffer overflow error was coming.

https://github.sec.samsung.net/RS7-IOTIVITY/IoTivity/pull/578/commits/e51cc0061628ab0fb7710ed3a5c3df08b61e2d5a
(cherry-picked from e51cc0061628ab0fb7710ed3a5c3df08b61e2d5a)

Change-Id: I65e5092c8b9c230b4394dd6239706b5f2d28fd36
Signed-off-by: Kush <kush.agrawal@samsung.com>
Signed-off-by: himanshu <h.himanshu@samsung.com>