EncodingFilter handles 'Accept-Encoding' header with empty String awkwardly

[tkroehli]

The class org.glassfish.jersey.server.filter.EncodingFillter only checks if the list of values for the 'Accept-Encoding' header is empty but not if a value in the list is empty. A reader is used in ContentEncoding#fromString for this value and the method hasNext is called, but its result is unused. This leads to a ParseException when nextToken is called for an empty String.
The exception does not lead to errors as it is caught, but still it can lead to lots of unnecessary exceptions and logging output.

[senivam]

fixed