server/tests.at: Fix TRIPECTL_INTERACT argument order.

server/tests.at: Fix TRIPECTL_INTERACT argument order.

For some reason, the TRIPECTL_INTERACT macro reverses its arguments,
making the first be an argument to `tripectl' and the second be the
script to connect to it.  Only neither call site actually passes the
second argument; instead, both of them pass the script in the first.
Since actually the script begins with a newline, it gets run after
`tripectl' finishes in the same side of the coprocess lash-up.

I have no idea how this has ever worked in the past.  I certainly know
that it doesn't work any more.  So fix it.