Get API URL from /etc/crowdsec/local_api_credentials.yaml

[blotus]

When installing the package, we should pull the LAPI URL from /etc/crowdsec/local_api_credentials.yaml, and add it to the configuration.
If the file is not present (or invalid), we should fallback to the current default (127.0.0.1:8080)

[LaurenceJJones]

Resolved already on master branch? can we just close @mmetc

[mmetc]

No, and since the issue is old I'd like to be sure if it's still something we want to do (presumably for the other bouncers too)

parsing yaml with bin/sh is not something to do on a whim :)