Allow for overriding UWSGI mount path

This is just one piece of the puzzle as I try to add support for URL prefixing.

tools/ansible/roles/dockerfile/files/uwsgi.ini

@@ -5,7 +5,15 @@ master = true
 vacuum = true
 no-orphans = true
 lazy-apps = true
+manage-script-name = true
 master-fifo = /var/lib/awx/awxfifo
 max-requests = 1000
 buffer-size = 32768
-module = awx.wsgi:application
+
+if-env = UWSGI_MOUNT_PATH
+mount = %(_)=awx.wsgi:application
+endif =
+
+if-not-env = UWSGI_MOUNT_PATH
+mount = /=awx.wsgi:application
+endif =