Unknown port --- assume yes they'll buy our cargo.

galaxy.py

@@ -232,6 +232,7 @@ class GameData(object):
         if port["port"][cargo_index] == "S":
             log.warn("port_buying( {0}, {1}): not buying cargo".format(sector, cargo))
             return False
+
         # ok, they buy it, but *WILL THEY* really buy it?
         cargo_key = cargo_types[cargo_index]
         if cargo_key in port:
@@ -242,6 +243,7 @@ class GameData(object):
                     )
                 )
                 return True
+        else return True  # unknown port, we're guess yes.
         return False
 
     @staticmethod