BUG/MINOR: http-ana: Reset analyse_exp date after 'wait-for-body' action

BUG/MINOR: http-ana: Reset analyse_exp date after 'wait-for-body' action

'wait-for-body' action set analyse_exp date for the channel to the
configured time. However, when the action is finished, it does not reset
it. It is an issue for some following actions, like 'pause', that also rely
on this date.

To fix the issue, we must take care to reset the analyse_exp date to
TICK_ETERNITY when the 'wait-for-body' action is finished.

This patch should fix the issue #3147. It must be backported to all stable
versions.