UriBuilder is not working with IPv6 link local addresses
Details about link local addresses: https://en.wikipedia.org/wiki/IPv6_address#Link-local_addresses_and_zone_indices

This bug is followup to RESTEASY-1718 work.

Commented-out check for link-local address is here: https://github.com/rsvoboda/Resteasy/commit/dbdd56b699b951a19defe7a5c04aaa3f6c5dc960#diff-1437cae1c96c188bce56dbecd344a21aR1086
Feel free to cherry pick that commit and use it in the fix PR

Assert.assertEquals("http://fe80::7:8%eth0", UriBuilder.fromUri("http://fe80::7:8%eth0").build().toString());
Assert.assertEquals("http://fe80::7:8%1", UriBuilder.fromUri("http://fe80::7:8%1").build().toString());