avoid URISyntaxException thrown on broken links

if page links to a broken URI like
“https://hostname.tld/#something=blah|somethingelse=blah1” whole
crawljax crashes on “java.net.URISyntaxException: Illegal character in
fragment at index 36:
https://hostname.tld/#something=blah|somethingelse=blah1”.

It’s kind of obvious as RFC3968
(http://tools.ietf.org/html/rfc3986#page-24), Fragment should not
contain a pipe “|” character (and also others).

This, however, should not break crawling itself.