MINOR: ssl/cli: update pointer to store in 'commit ssl cert'

MINOR: ssl/cli: update pointer to store in 'commit ssl cert'

The crtlist_entry structure use a pointer to the store as key.
That's a problem with the dynamic update of a certificate over the CLI,
because it allocates a new ckch_store. So updating the pointers is
needed. To achieve that, a linked list of the crtlist_entry was added in
the ckch_store, so it's easy to iterate on this list to update the
pointers. Another solution would have been to rework the system so we
don't allocate a new ckch_store, but it requires a rework of the ckch
code.