Fix for issue related to https://webarchive.jira.com/browse/ARI-3637

When http://wayback.archive-it.org/4266/*/http://cade.com.br is accessed, the code assumes the length of the surt "http://(br,com,cade,www,)" is at least 2 greater than endOfAuthority if pos == endOfAuthority. This causes a java.lang.StringIndexOutOfBoundsException.

Not sure if this is the correct way to fix...please review.