Your server has started normally. The Lua JIT interpreter might be disabled due to a missing dependency. Make sure that you have the Lua binary and devel packages off of apt-get. The Lua JIT interpreter might be disabled due to a missing dependency. Make sure that you have the Lua binary and devel packages off of apt-get.
I run a dedicated Garry's Mod server off of my local computer. In order to connect to my own server, I needed to use my external IP address to connect. Try connect <your external>:27015.
EDIT: The Lua JIT interpreter is disabled by default on purpose due to FPS issues. If you want to turn it on, add -withjit to your launch command.