DERBY-6085: Improve error reporting when server port is unavailable

Added port and host to error message.

Patch file: derby-6085-1a-port_host_errmsg.diff


git-svn-id: https://svn.apache.org/repos/asf/db/derby/code/trunk@1448441 13f79535-47bb-0310-9956-ffa450edef68