hg: amber/amber/langtools: update error message for _

[vicente.romero at oracle.com]

Changeset: f38ae827457b
Author:    vromero
Date:      2017-04-14 11:52 -0700
URL:       http://hg.openjdk.java.net/amber/amber/langtools/rev/f38ae827457b

update error message for _

! src/jdk.compiler/share/classes/com/sun/tools/javac/resources/compiler.properties