Bump JXMPP to 0.6.3
Bump JXMPP to 0.6.3

vanitasvitae/Smack,Flowdalic/Smack,vanitasvitae/Smack,Flowdalic/Smack,Flowdalic/Smack,igniterealtime/Smack,vanitasvitae/Smack,igniterealtime/Smack,igniterealtime/Smack