trackman: wrap stream listeners fetch in a try
trackman: wrap stream listeners fetch in a try

This will prevent the stream server being unreachable from preventing
track logging. This will still log an error, which will then be
emailed/otherwise handled.

Fixes #140.

wuvt/wuvt-site,wuvt/wuvt-site,wuvt/wuvt-site,wuvt/wuvt-site