Fix Devcontainer Port Mapping

This change should be a one-liner.

As it currently stands, the only way to see the mysql database while developing is by running commands via a command line inside the mysql container. You can run vscode and connect to the devcontainer and run `mysql -u lsf_user -ppassword` and it'll work. If you'd like to run it in a separate terminal, however, we aren't exposing a port to the mysql server. We are exposing port `3308:3308` but inside the container, there seems to be nothing listening to 3308. Since a mysql server runs on the default port 3306, we can't currently create a mysql connection via a terminal outside of the dev container.

`mysql -u lsf_user -ppassword -h 127.0.0.1 -P 3308` should connect to the server

Since it doesn't, we should change the port mapping of the db to `3308:3306`.