Inconsistencies in back-sql samples (ITS#2639)

[emmanuel.duru@atosorigin.com]

Full_Name: Emmanuel Duru
Version: 2.2.0 alpha
OS: solaris 8
URL: 
Submission from: (NULL) (195.68.44.148)


* in oracle, the dn_ru colum is declared in the SQL tables definition, but is
not filled in the data sample, which makes the search requests not match (either
fill the dn_ru's, or set has_ldapinfo_dn_ru to no in the slapd.conf sample).
* in mysql, there misses the definition of the sel_expr_u column in the
ldap_attr_mappings table definition, which makes the server crash at startup.