Fix error message on unsupported protocols
Fix error message on unsupported protocols

leafo/luarocks,starius/luarocks,coderstudy/luarocks,robooo/luarocks,robooo/luarocks,aryajur/luarocks,tarantool/luarocks,xpol/luainstaller,xpol/luarocks,xpol/luainstaller,ignacio/luarocks,xpol/luarocks,usstwxy/luarocks,luarocks/luarocks,aryajur/luarocks,usstwxy/luarocks,robooo/luarocks,luarocks/luarocks,leafo/luarocks,xpol/luarocks,lxbgit/luarocks,usstwxy/luarocks,xpol/luainstaller,tst2005/luarocks,tst2005/luarocks,ignacio/luarocks,ignacio/luarocks,lxbgit/luarocks,keplerproject/luarocks,keplerproject/luarocks,tst2005/luarocks,xpol/luavm,xpol/luavm,tarantool/luarocks,rrthomas/luarocks,starius/luarocks,coderstudy/luarocks,tarantool/luarocks,rrthomas/luarocks,xiaq/luarocks,keplerproject/luarocks,xiaq/luarocks,xiaq/luarocks,rrthomas/luarocks,xpol/luavm,coderstudy/luarocks,coderstudy/luarocks,robooo/luarocks,xiaq/luarocks,rrthomas/luarocks,luarocks/luarocks,xpol/luarocks,xpol/luavm,lxbgit/luarocks,xpol/luainstaller,starius/luarocks,lxbgit/luarocks,starius/luarocks,tst2005/luarocks,keplerproject/luarocks,usstwxy/luarocks,aryajur/luarocks,leafo/luarocks,xpol/luavm,aryajur/luarocks,ignacio/luarocks