Unregister bundle callbacks to avoid abort

Unregister bundle callbacks to avoid abort

[Issue#] N_SE-13058
[Problem] WRT abort occurs when emula
[Cause] Webkit invoke callbacks on object which is not available.
[Solution] Unregister callbacks from webkit
[SCMRequest] N/A

Verification :
(On emulator)
1. Run Intel hangonman
2. Right click on emulator window
3. Close (emulator)
4. Ok (to confirm)
5. Start the emulator again
6. Go SLP bugs folder in connection explorer
(/opt/share/hidden_storage/SLP_debug) check that new file with bug trace
does not appear

Change-Id: Iab5c211822dcec748cb2f3765d90a007d4e669f4