oxdisco: rectify public folder mailboxid generation

The AutoDiscover responder emitted the wrong mailboxid for public
stores. This has no consequences because the MailboxId parameter is
unused except for displaying debug strings, and the actual mailbox
name is in the ropLogon payload instead.

Author: jengelh

exch/oxdisco.cpp

@@ -668,6 +668,9 @@ int OxdiscoPlugin::resp_web(XMLElement *el, const char *authuser,
 	}
 	else {
 		DisplayName = public_folder;
+		unsigned int org_id = 0;
+		if (!mysql_adaptor_get_domain_ids(domain, &domain_id, &org_id))
+			return -1;
 		if (cvt_username_to_essdn(email, x500_org_name.c_str(),
 		    mysql_adaptor_get_user_ids, mysql_adaptor_get_domain_ids,
 		    essdn) != ecSuccess)