build: Fixed building without zlib.
build: Fixed building without zlib.

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