channel: fix setting of channel->flags
channel: fix setting of channel->flags

Fix the setting of 'channel->flags' to use '|='.  Before this
change, one bug symptom can be that channels are never fully
free'd via ssh_channel_free, resulting in memory leaks.

Reviewed-by: Andreas Schneider <5be00ddc76278cf6077f5047ca3384a88460c671@cryptomilk.org>

pouete/libssh,kedazo/libssh,nviennot/libssh,taikoo/libssh,robxu9/libssh,elastichosts/libssh,robxu9/libssh,wangshawn/libssh,nviennot/libssh,mwgoldsmith/libssh,robxu9/libssh,wangshawn/libssh,pouete/libssh,kedazo/libssh,nviennot/libssh,mwgoldsmith/libssh,Distrotech/libssh,DouglasHeriot/libssh,elastichosts/libssh,Distrotech/libssh,mwgoldsmith/ssh,mwgoldsmith/libssh,Distrotech/libssh,elastichosts/libssh,taikoo/libssh,taikoo/libssh,sebadoom/libssh,DouglasHeriot/libssh,pouete/libssh,sebadoom/libssh,sebadoom/libssh,robxu9/libssh,mwgoldsmith/libssh,wangshawn/libssh,pouete/libssh,mwgoldsmith/ssh,sebadoom/libssh,kedazo/libssh,taikoo/libssh,nviennot/libssh,DouglasHeriot/libssh,kedazo/libssh,Distrotech/libssh,mwgoldsmith/ssh,mwgoldsmith/ssh,wangshawn/libssh,DouglasHeriot/libssh