RFR: JDK-8231279: Change install location for copyright file for Debian package

[Alexey Semenyuk]

Please review the jpackage fix for bug [1] at [2].

This is a fix for the JDK-8200758-branch branch of the open sandbox 
repository (jpackage).

Baseline for the fix is [3] patch.

[1] https://bugs.openjdk.java.net/browse/JDK-8231279

[2] http://cr.openjdk.java.net/~asemenyuk/8231279/webrev.01/

[3] http://cr.openjdk.java.net/~asemenyuk/8231277/webrev.00/