reaper was not deleting expired sessions the TTL had a wrong value.

i was trying out giallo_session and found that expired sessions were never deleted. Looking around the code i saw that in the handle_info where the sessions are deleted, the TTL format was not correct : 

TTL = giallo_session_config:ttl(). This returns  : {ok, ttl_time}

afterwards, it is compared with seconds_since(). Well, this comparation is always false : seconds_since() > TTL = false.

The only change to make for it to work is {ok,TTL} = giallo_session_config:ttl().