Improve "Grant Access" template when client requests only openid scope

Fixes #1732

Signed-off-by: Brian Candler <b.candler@pobox.com>

web/templates/approval.html

@@ -5,12 +5,16 @@
 
   <hr class="dex-separator">
   <div>
+    {{ if .Scopes }}
     <div class="dex-subtle-text">{{ .Client }} would like to:</div>
     <ul class="dex-list">
       {{ range $scope := .Scopes }}
       <li>{{ $scope }}</li>
       {{ end }}
     </ul>
+    {{ else }}
+    <div class="dex-subtle-text">{{ .Client }} has not requested any personal information</div>
+    {{ end }}
   </div>
   <hr class="dex-separator">