[11]RFR 8194152: sun/security/tools/jarsigner/AltProvider.java failed on de-DE locale

[Dora Zhou]

Hello,

Please help review the fix for JDK-8194152. Thank you.
The test compares output with expected error messages in English, set 
locale to en-US so that the output are not translated into other languages.

Bug: https://bugs.openjdk.java.net/browse/JDK-8194152
Webrev: http://cr.openjdk.java.net/~ljiang/8194152/webrev/ 
<http://cr.openjdk.java.net/%7Eljiang/8194152/webrev/>

Regards,
Dora