Add timeout for guac postgres queries

[craddm]

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⤴️ Summary

Adds a timeout for PostGRES sockets when Guacamole tries to connect to the database

🌂 Related issues

Closes #1607

🔬 Tests

[JimMadge]

LGTM, are we still testing this change?

[jemrobinson]

Testing is ongoing. @craddm to confirm if/when we're happy.

[craddm]

So far so good. Since the issue seems to relate to periods of inactivity, I'd say if everything is still fine tomorrow morning, this has done the trick.

[craddm]

No further issues today, so seems like this worked.