Fix aodh wsgi config file in Debuntu binary

This patch is fixing file path for WSGIScriptAlias
as debian/ubuntu binary packages installs /usr/bin/aodh-api
as it is in source images also. For details please check
LP bug report.

Closes-Bug: #1953059
Change-Id: I9efe73193bf828b084c2844be73c9813a969c9c7