adding libpq to pgbouncer breaks single handler

Having a weird issue that I just can't figure out. We are playing
with implementing listen/notify in pgbouncer. Our strategy involved
some libpq calls etc so we added libpq to the make. Doing this
completely broke pgbouncer signals...something else is catching
SIGINT. If we comment our function that makes libpq calls (with the
linker thereby optimizing out the libpq stuff), the problem goes away.
Note none of our code actually, runs, we manually raise a kill
immediately after setting up signals in pgbouncer and it doesn't get
properly caught if we have libpq linked in.

merlin