BUG/MEDIUM: counters: fix track-sc* to wait on unstable contents

I've been facing multiple configurations which involved track-sc* rules
in tcp-request content without the "if ..." to force it to wait for the
contents, resulting in random behaviour with contents sometimes retrieved
and sometimes not.

Reading the doc doesn't make it clear either that the tracking will be
performed only if data are already there and that waiting on an ACL is
the only way to avoid this.

Since this behaviour is not natural and we now have the ability to fix
it, this patch ensures that if input data are still moving, instead of
silently dropping them, we naturally wait for them to stabilize up to
the inspect-delay. This way it's not needed anymore to implement an
ACL-based condition to force to wait for data, eventhough the behaviour
is not changed for when an ACL is present.

The most obvious usage will be when track-sc is followed by any HTTP
sample expression, there's no need anymore for adding "if HTTP".

It's probably worth backporting this to 1.5 to avoid further configuration
issues. Note that it requires previous patch.
(cherry picked from commit 1b71eb581ec1637879f725421efb95ad69f0ea4f)
1 file changed