Prevent NPE if no email and not name

Author: vjrj

grails-app/services/au/org/ala/collectory/EmlImportService.groovy

@@ -187,6 +187,8 @@ class EmlImportService {
 
         if (!contact && (hasEmail || hasName)) {
             contact = new Contact()
+        } else {
+            return null
         }
 
         // Update the contact details