(ITS#7773) slapo-constraint falsely restricts modrdn with count 1

[michael@stroeder.com]

Full_Name: 
Version: 2.4.38
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Submission from: (NULL) (212.227.35.93)


Sometimes it's useful to restrict an existing attribute type declared
multi-valued to a single value with slapo-constraint to avoid modifying the
standard schema.

Example:

constraint_attribute
  uid
  count 1
  restrict="ldap:///ou=example??sub?(objectClass=account)"

Unfortunately when using uid in the RDN one cannot rename the entry anymore even
when deleteoldrdn is set to true.

slapo-constraint should handle this case exactly like SINGLE-VALUE RDN
attributes are handled.