Contact update fails for objects with disclosed attributes

[vohmar]

Related to #2272

disclosed attributes affect only visibility of the parameter in primarily whois/rest-whois by overriding the default visibility settings. It must not affect the possibility to update contact data like email address, phone number or name.

but currently any attempt to update a contact with disclosed attributes results with

<result code="2005">
      <msg lang="en">Contact contains unsupported attribute(s) [disclosed_attributes]</msg>