servers: webserver: If binding the http port fails, retry it up to 60 seconds...

servers: webserver: If binding the http port fails, retry it up to 60 seconds in case of an "Address already in use" error.

This is necessary because the Sun webserver does not allow to specify the SO_REUSEADDR socket option. For this reason, we're seeing flaky unit test executions in the nightly tests. This should fix it.