transport: distinguish between unknown and unsupported transports
transport: distinguish between unknown and unsupported transports

Even when built without a SSH support, we know about this transport. It
is implemented, but the current code makes us return an error message
saying it's not.

This is a leftover from the initial implementation of the transports
when there were in fact transports we knew about but were not
implemented.

Instead, let the SSH transport itself say it cannot run, the same as we
do for HTTPS.

nokiddin/libgit2,swisspol/DEMO-libgit2,dleehr/libgit2,skabel/manguse,Corillian/libgit2,ardumont/libgit2,kenprice/libgit2,skabel/manguse,saurabhsuniljain/libgit2,mhp/libgit2,t0xicCode/libgit2,JIghtuse/libgit2,raybrad/libit2,kissthink/libgit2,sim0629/libgit2,sim0629/libgit2,JIghtuse/libgit2,mcanthony/libgit2,ardumont/libgit2,falqas/libgit2,joshtriplett/libgit2,mcanthony/libgit2,jeffhostetler/public_libgit2,yongthecoder/libgit2,Tousiph/Demo1,MrHacky/libgit2,amyvmiwei/libgit2,iankronquist/libgit2,mrksrm/Mingijura,nokiddin/libgit2,maxiaoqian/libgit2,chiayolin/libgit2,yongthecoder/libgit2,kissthink/libgit2,swisspol/DEMO-libgit2,chiayolin/libgit2,raybrad/libit2,Corillian/libgit2,joshtriplett/libgit2,iankronquist/libgit2,skabel/manguse,spraints/libgit2,KTXSoftware/libgit2,claudelee/libgit2,t0xicCode/libgit2,falqas/libgit2,magnus98/TEST,claudelee/libgit2,JIghtuse/libgit2,yosefhackmon/libgit2,whoisj/libgit2,whoisj/libgit2,stewid/libgit2,sim0629/libgit2,swisspol/DEMO-libgit2,linquize/libgit2,yongthecoder/libgit2,mrksrm/Mingijura,maxiaoqian/libgit2,saurabhsuniljain/libgit2,since2014/libgit2,jeffhostetler/public_libgit2,chiayolin/libgit2,raybrad/libit2,saurabhsuniljain/libgit2,spraints/libgit2,oaastest/libgit2,joshtriplett/libgit2,magnus98/TEST,claudelee/libgit2,jeffhostetler/public_libgit2,MrHacky/libgit2,kissthink/libgit2,since2014/libgit2,sim0629/libgit2,jflesch/libgit2-mariadb,rcorre/libgit2,whoisj/libgit2,mhp/libgit2,whoisj/libgit2,kenprice/libgit2,jflesch/libgit2-mariadb,yosefhackmon/libgit2,stewid/libgit2,iankronquist/libgit2,rcorre/libgit2,dleehr/libgit2,Snazz2001/libgit2,swisspol/DEMO-libgit2,mingyaaaa/libgit2,KTXSoftware/libgit2,chiayolin/libgit2,mcanthony/libgit2,mrksrm/Mingijura,mingyaaaa/libgit2,mcanthony/libgit2,sim0629/libgit2,ardumont/libgit2,rcorre/libgit2,Tousiph/Demo1,MrHacky/libgit2,claudelee/libgit2,jflesch/libgit2-mariadb,jeffhostetler/public_libgit2,linquize/libgit2,oaastest/libgit2,leoyanggit/libgit2,leoyanggit/libgit2,since2014/libgit2,mingyaaaa/libgit2,since2014/libgit2,mrksrm/Mingijura,joshtriplett/libgit2,nokiddin/libgit2,jeffhostetler/public_libgit2,KTXSoftware/libgit2,mhp/libgit2,saurabhsuniljain/libgit2,mrksrm/Mingijura,amyvmiwei/libgit2,skabel/manguse,Snazz2001/libgit2,linquize/libgit2,rcorre/libgit2,jflesch/libgit2-mariadb,amyvmiwei/libgit2,rcorre/libgit2,maxiaoqian/libgit2,stewid/libgit2,skabel/manguse,yosefhackmon/libgit2,skabel/manguse,spraints/libgit2,MrHacky/libgit2,amyvmiwei/libgit2,iankronquist/libgit2,MrHacky/libgit2,claudelee/libgit2,mingyaaaa/libgit2,nokiddin/libgit2,since2014/libgit2,amyvmiwei/libgit2,Snazz2001/libgit2,amyvmiwei/libgit2,Corillian/libgit2,mcanthony/libgit2,ardumont/libgit2,MrHacky/libgit2,Corillian/libgit2,magnus98/TEST,Snazz2001/libgit2,swisspol/DEMO-libgit2,mingyaaaa/libgit2,falqas/libgit2,yongthecoder/libgit2,JIghtuse/libgit2,Corillian/libgit2,raybrad/libit2,chiayolin/libgit2,maxiaoqian/libgit2,whoisj/libgit2,KTXSoftware/libgit2,iankronquist/libgit2,sygool/libgit2,dleehr/libgit2,sygool/libgit2,nokiddin/libgit2,mhp/libgit2,stewid/libgit2,linquize/libgit2,spraints/libgit2,jflesch/libgit2-mariadb,joshtriplett/libgit2,Corillian/libgit2,leoyanggit/libgit2,swisspol/DEMO-libgit2,yongthecoder/libgit2,kenprice/libgit2,joshtriplett/libgit2,kissthink/libgit2,sygool/libgit2,saurabhsuniljain/libgit2,t0xicCode/libgit2,spraints/libgit2,chiayolin/libgit2,mrksrm/Mingijura,kenprice/libgit2,kissthink/libgit2,t0xicCode/libgit2,sygool/libgit2,linquize/libgit2,JIghtuse/libgit2,Snazz2001/libgit2,falqas/libgit2,maxiaoqian/libgit2,magnus98/TEST,falqas/libgit2,maxiaoqian/libgit2,kenprice/libgit2,Tousiph/Demo1,mhp/libgit2,nokiddin/libgit2,KTXSoftware/libgit2,yosefhackmon/libgit2,sygool/libgit2,Tousiph/Demo1,leoyanggit/libgit2,leoyanggit/libgit2,claudelee/libgit2,jflesch/libgit2-mariadb,oaastest/libgit2,magnus98/TEST,stewid/libgit2,mhp/libgit2,Tousiph/Demo1,oaastest/libgit2,linquize/libgit2,kissthink/libgit2,dleehr/libgit2,Tousiph/Demo1,since2014/libgit2,iankronquist/libgit2,leoyanggit/libgit2,mcanthony/libgit2,JIghtuse/libgit2,raybrad/libit2,kenprice/libgit2,yongthecoder/libgit2,dleehr/libgit2,KTXSoftware/libgit2,dleehr/libgit2,oaastest/libgit2,magnus98/TEST,ardumont/libgit2,Snazz2001/libgit2,yosefhackmon/libgit2,yosefhackmon/libgit2,saurabhsuniljain/libgit2,sygool/libgit2,mingyaaaa/libgit2,spraints/libgit2,t0xicCode/libgit2,t0xicCode/libgit2,whoisj/libgit2,rcorre/libgit2,falqas/libgit2,stewid/libgit2,ardumont/libgit2,oaastest/libgit2,jeffhostetler/public_libgit2,sim0629/libgit2