pbx/pbx_spool: Fix issue when call files were executed too early

pbx_spool used to delete/move the call file upon successful outgoing
call completion, but did not delete it from in-memory list of files
(dirlist, used only when compiled with inotify/kqueue support).
That resulted in an extra attempt to process that filename after
retrytime seconds.
Then, if a new file with the same name appears that is scheduled
in future further than the completed one plus its retrytime,
then it gets executed earlier than expected.

This patch fixes remove_from_queue function to also remove the entry
from the dirlist.

ASTERISK-17069 #close
Reported by: Jeremy Kister

ASTERISK-24442 #close
Reported by: tootai

Change-Id: If9ec9b88073661ce485d6b008fd0b2612e49a28b