DERBY-6457; NetworkServerControl API breaks when username or password contains non-ascii characters
   backport of revision 1560311 from trunk. Original fix / patch contributed by Knut Anders Hatlen


git-svn-id: https://svn.apache.org/repos/asf/db/derby/code/branches/10.10@1572384 13f79535-47bb-0310-9956-ffa450edef68