avoid rebroadcasting presence if there is no initial presence sent yet; fix NPE in pep #3372
avoid rebroadcasting presence if there is no initial presence sent yet; fix NPE in pep #3372

caiyingyuan/tigase71,amikey/tigase-server,amikey/tigase-server,caiyingyuan/tigase71,caiyingyuan/tigase71,caiyingyuan/tigase71,caiyingyuan/tigase71,amikey/tigase-server,caiyingyuan/tigase71,amikey/tigase-server,amikey/tigase-server,amikey/tigase-server