mon: Paxos: reset accept timeout before submiting work to the store

Otherwise we may trigger the timeout while waiting for the work to be
committed to the store -- and it would only take the write to take a bit
longer than 10 seconds (default accept timeout).

We do wait for the work to be properly committed to the store before
extending the lease though.

Fixes: #10220

Signed-off-by: Joao Eduardo Luis <joao@redhat.com>