[bug,patch] Jabber connection timeout

[Shmuma]

Hello,

recently I noticed that jabber notifications stop working after several hours since zabbix_server restart. This occurs because of bug in zbx_io_send routine, which won't handle the case when jabber server connection becomes unavailable (timeout, server restart, etc). Patch attached.

[nevzorofff]

This patch doesn't apply yet in 1.6.2? I didn't see it in release notes.