Fix WP8 first register error
Fix WP8 first register error

FIX Problem when first register in wp8 doesn't work because callback not
initialize before call to open.

sylvaindeloux/PushPlugin,hgo/PushPlugin,safetychanger/PushPlugin,johnvandeweghe/PushPlugin,hgo/PushPlugin,baozhoutao/PushPlugin,mitiaptest/pushNotification,linalu1/PushPlugin,noahxinhao/PushPlugin,Sharinglabs/PushPlugin,noahxinhao/PushPlugin,Mobii/PushPlugin,IWAtech/PushPlugin,Sharinglabs/PushPlugin,phonegap-build/PushPlugin,reinalde/PushPlugin,johnvandeweghe/PushPlugin,Sharinglabs/PushPlugin,accomplix/PushPlugin,barryvdh/PushPlugin,yossale/PushPlugin,kozzztya/PushPlugin,sylvaindeloux/PushPlugin,motorro/PushPlugin,hgo/PushPlugin,noahxinhao/PushPlugin,EET-India/PushPlugin,tsimoli/PushPlugin,msun/PushPlugin,deboorn/PushPlugin,sylvaindeloux/PushPlugin,EET-India/PushPlugin,IWAtech/PushPlugin,msun/PushPlugin,reinalde/PushPlugin,yossale/PushPlugin,phonegap-build/PushPlugin,EET-India/PushPlugin,kozzztya/PushPlugin,IWAtech/PushPlugin,kozzztya/PushPlugin,motorro/PushPlugin,steedos/PushPlugin-Baidu,kozzztya/PushPlugin,safetychanger/PushPlugin,mitiaptest/pushNotification,EET-India/PushPlugin,barryvdh/PushPlugin,yossale/PushPlugin,motorro/PushPlugin,deboorn/PushPlugin,gabrielkwok/PushPlugin,johnvandeweghe/PushPlugin,steedos/PushPlugin-Baidu,reinalde/PushPlugin,baozhoutao/PushPlugin,linalu1/PushPlugin,safetychanger/PushPlugin,phonegap-build/PushPlugin,linalu1/PushPlugin,baozhoutao/PushPlugin,johnvandeweghe/PushPlugin,IWAtech/PushPlugin,deboorn/PushPlugin,barryvdh/PushPlugin,Mobii/PushPlugin,tsimoli/PushPlugin,gabrielkwok/PushPlugin,msun/PushPlugin,linalu1/PushPlugin,mitiaptest/pushNotification,phonegap-build/PushPlugin,noahxinhao/PushPlugin,deboorn/PushPlugin,IWAtech/PushPlugin,accomplix/PushPlugin,motorro/PushPlugin,steedos/PushPlugin-Baidu,safetychanger/PushPlugin,tsimoli/PushPlugin,barryvdh/PushPlugin,gabrielkwok/PushPlugin,motorro/PushPlugin,reinalde/PushPlugin,Mobii/PushPlugin,gabrielkwok/PushPlugin,mitiaptest/pushNotification,baozhoutao/PushPlugin,msun/PushPlugin,sylvaindeloux/PushPlugin,EET-India/PushPlugin,Sharinglabs/PushPlugin,kozzztya/PushPlugin,reinalde/PushPlugin,accomplix/PushPlugin,accomplix/PushPlugin,steedos/PushPlugin-Baidu,accomplix/PushPlugin,sylvaindeloux/PushPlugin,phonegap-build/PushPlugin,safetychanger/PushPlugin,tsimoli/PushPlugin,Mobii/PushPlugin,barryvdh/PushPlugin,Sharinglabs/PushPlugin,Mobii/PushPlugin,baozhoutao/PushPlugin,hgo/PushPlugin,tsimoli/PushPlugin,mitiaptest/pushNotification,johnvandeweghe/PushPlugin,noahxinhao/PushPlugin,msun/PushPlugin,linalu1/PushPlugin,yossale/PushPlugin,hgo/PushPlugin,yossale/PushPlugin,steedos/PushPlugin-Baidu,deboorn/PushPlugin,gabrielkwok/PushPlugin