(ITS#6024) Don't send cookie with without csn field

[rein@OpenLDAP.org]

Full_Name: Rein Tollevik
Version: CVS HEAD
OS: Irrelevant
URL: 
Submission from: (NULL) (84.215.36.97)
Submitted by: rein


Syncprov sends a cookie to its consumer even when it doesn't have any csn
values, i.e the cookie will only have the rid= and sid= fields.  This can happen
during initial load (as in test050) when a syncrepl consumer enters the present
phase before the provider have finished the refresh phase with its own
provider.

This doesn't seem to harm the consumer, as it appears to silently ignore these
cookies.  But it can be confusing for somone trying to analyze the logs..  A fix
is coming.

Rein Tollevik
Basefarm AS