[2.3.x] + fix issue #1638
https://java.net/jira/browse/GRIZZLY-1638
"Http Mapper stopped to resolve virtual hosts due to a typo"

+ unit test added
[2.3.x] + fix issue #1637
https://java.net/jira/browse/GRIZZLY-1637
"request.setCharacterEncoding(xxx) breaks request.getContentType()"

+ unit test added