Fix tests on Windows with Lua 5.3
Fix tests on Windows with Lua 5.3

Don't install luafilesystem 1.6.1 on Windows with Lua 5.3, it
fails.

tarantool/luarocks,xpol/luainstaller,keplerproject/luarocks,xpol/luavm,keplerproject/luarocks,xpol/luavm,robooo/luarocks,luarocks/luarocks,luarocks/luarocks,xpol/luavm,xpol/luainstaller,tarantool/luarocks,robooo/luarocks,robooo/luarocks,xpol/luavm,xpol/luainstaller,xpol/luainstaller,xpol/luavm,robooo/luarocks,xpol/luarocks,keplerproject/luarocks,xpol/luarocks,keplerproject/luarocks,xpol/luarocks,luarocks/luarocks,xpol/luarocks,tarantool/luarocks