fix the bug that app crash
fix the bug that app crash

Object is realsed in the different thread which cocos-2d is not thread safety.
MobClub/C2DXShareSDKSample,ShareSDKPlatform/C2DXShareSDKSample,ShareSDKPlatform/C2DXShareSDKSample,ShareSDKPlatform/C2DXShareSDKSample,ShareSDKPlatform/C2DXShareSDKSample,MobClub/C2DXShareSDKSample,MobClub/C2DXShareSDKSample,MobClub/C2DXShareSDKSample