Clarify missing_required_fields to note that validation could have not succeeded

Closes: #194

Author: thijskh

languages/messages.en.php

@@ -200,7 +200,7 @@
     'error_generic_desc_no_names' => 'Logging in has failed and we don\'t know exactly why. Please try again first by going back to the service and logging in again. If this doesn\'t work, please contact the service desk of your %organisationNoun%.',
     'error_missing_required_fields'     => 'Error - Missing required fields',
     'error_missing_required_fields_desc'=> '<p>
-%idpName% does not provide the mandatory information. Therefore, you can not use %spName%. Please contact the service desk of %idpName% and tell them one or more of the the following required attribute(s) are missing within %suiteName%:
+%idpName% does not provide the mandatory information or it has an invalid format. Therefore, you can not use %spName%. Please contact the service desk of %idpName% and tell them one or more of the the following required attributes are not being set correctly for %suiteName%:
 </p>
 <p>
     <ul>

languages/messages.nl.php

@@ -203,7 +203,7 @@
         Neem alstublieft contact op met de helpdesk van %idpName%. Geef hierbij de onderstaande informatie door.
     </p>
     <p>
-        Omdat %idpName% niet de juiste attributen aan %suiteName% doorgeeft is het inloggen mislukt. De volgende attributen zijn vereist om succesvol in te loggen op het %suiteName% platform:
+        Omdat %idpName% niet de juiste attributen aan %suiteName% doorgeeft, of in het onjuiste formaat, is het inloggen mislukt. De volgende attributen zijn vereist om succesvol in te loggen op het %suiteName% platform:
         <ul>
             <li>UID</li>
             <li>schacHomeOrganization</li>