It is possible to save a space (" ") character in place of a required configuration item

Steps to Reproduce

1. Add a directory to Crowd
2. Replace one of the required attributes on the Configuration page with a " " character
3. Save the page
   • Expected result - this would fail
   • Actual result - the page saves successfully
4. Attempt to sync however, and you will see errors like this:

   2013-02-06 11:40:13,680 http-8095-11 FATAL [springframework.ldap.control.AbstractRequestControlDirContextProcessor] No matching response control found for paged results - looking for 'class javax.naming.ldap.PagedResultsResponseControl
   2013-02-06 11:40:13,680 http-8095-11 ERROR [console.action.principal.BrowsePrincipals] org.springframework.ldap.InvalidSearchFilterException: invalid attribute description; nested exception is javax.naming.directory.InvalidSearchFilterException: invalid attribute description; remaining name 'OU=Users,DC=company,DC=com,DC=au'
   com.atlassian.crowd.exception.OperationFailedException: org.springframework.ldap.InvalidSearchFilterException: invalid attribute description; nested exception is javax.naming.directory.InvalidSearchFilterException: invalid attribute description; remaining name 'OU=Users,DC=company,DC=com,DC=au'
   ...
   Caused by: org.springframework.ldap.InvalidSearchFilterException: invalid attribute description; nested exception is javax.naming.directory.InvalidSearchFilterException: invalid attribute description; remaining name 'OU=Users,DC=company,DC=com,DC=au'
   ...
   Caused by: javax.naming.directory.InvalidSearchFilterException: invalid attribute description; remaining name 'OU=Users,DC=company,DC=com,DC=au'