1990 Cavalier leaking coolant

My father-in-laws 1990 Cavalier (3.1L, V6, Z34) is leaking coolant from a small rubber tube that appears to come out of the heater core. This tube is just below two other metal pipes that go into/through the firewall on the right side. It is "L" shaped and does not appear to connect to anything, but I could be wrong. Is this an outlet for coolant if the heater core springs a leak, or does it serve another purpose? The book we purchased was no help and all the cavaliers I looked at at the junkyard din't have anything connected to this outlet either.

Thanks for any help you can provide.