Delete ttl tasks using delete method

[andyudina]

Now ttl tasks are deleted directly from queue: https://github.com/tarantool/queue/blob/master/queue/abstract/driver/fifottl.lua#L138
Should use delete method https://github.com/tarantool/queue/blob/master/queue/abstract/driver/fifottl.lua#L269 instead

[fsitedev]

Similar problem also on ttr tasks:
https://github.com/tarantool/queue/blob/master/queue/abstract/driver/fifottl.lua#L157