Verify existence of callback before using them
Verify existence of callback before using them

miloj/libssh-v0.5,mwgoldsmith/libssh,jahrome/libssh,kedazo/libssh,taikoo/libssh,taikoo/libssh,nviennot/libssh,rofl0r/libssh,pouete/libssh,jt1/honeypot-libssh,kedazo/libssh,Distrotech/libssh,taikoo/libssh,miloj/libssh-v0.5,taikoo/libssh,Distrotech/libssh,bigcat26/libssh-mod,kedazo/libssh,kedazo/libssh,jahrome/libssh,DouglasHeriot/libssh,robxu9/libssh,sebadoom/libssh,mwgoldsmith/ssh,pouete/libssh,robxu9/libssh,miloj/libssh-v0.5,rofl0r/libssh,sebadoom/libssh,nviennot/libssh,mwgoldsmith/ssh,jt1/honeypot-libssh,Distrotech/libssh,mwgoldsmith/libssh,DouglasHeriot/libssh,nviennot/libssh,jahrome/libssh,mwgoldsmith/libssh,bigcat26/libssh-mod,substack/libssh,rofl0r/libssh,pouete/libssh,sebadoom/libssh,jt1/honeypot-libssh,sebadoom/libssh,elastichosts/libssh,nviennot/libssh,jahrome/libssh,miloj/libssh-v0.5,substack/libssh,wangshawn/libssh,substack/libssh,elastichosts/libssh,mwgoldsmith/libssh,DouglasHeriot/libssh,substack/libssh,elastichosts/libssh,Distrotech/libssh,mwgoldsmith/ssh,wangshawn/libssh,pouete/libssh,robxu9/libssh,jt1/honeypot-libssh,bigcat26/libssh-mod,wangshawn/libssh,mwgoldsmith/ssh,robxu9/libssh,DouglasHeriot/libssh,wangshawn/libssh,rofl0r/libssh,bigcat26/libssh-mod