RFR: 8217364: Custom URLStreamHandler for jrt or file protocol can override default handler

[Seán Coffey]

Looking to correct an issue that arose during the JDK-8213942 fix.

https://bugs.openjdk.java.net/browse/JDK-8217364
https://cr.openjdk.java.net/~coffeys/webrev.8217364/webrev/

regards,
Sean.