OF-2490: Better handle PEP requests to non-local/non-registered users
Only local, registered users of Openfire have a PEP service. Other users do not. When a client tries to interact with such a non-existing PEP service, the current behavior of Openfire is to very verbosely log this as an (unexpected) error.
This code tries to properly handle this scenario, by returning a nice error back to the requestee, and logging it less verbosely.
OF-2489: Reduce log level severity of SOCKS5 error
Whenever a peer sends unexpected data to the file transfer proxy, an exception occurs. As this is not something that can be 'fixed' by an Openfire administrator, the error shouldn't be logged as verbosely as on level ERROR.
This commit reduces the log level on which this is logged, and improves the wording of the logged message a little.
OF-2488: Reduce log level severity of DNS lookup failure
When a particular DNS SRV record doesn't exist, there is no need to log this on level ERROR with a stack trace. The administrator of Openfire is unlikely to be able to fix this, while it occurs all the time.
