AbstractLoggingHandler fails to log activity if an exception is thrown

[paulmillar]

The class org.dcache.http.AbstractLoggingHandler contains the handle method to process requests.

For non-async requests, this handle method calls requestCompleted directly, to record the activity after the request was processed (see super.handle).

However, the if super.handle throws an exception then requestCompleted is not called and the request is not logged in the access log file.