oidc: better error page message

src/oidc.js

@@ -528,7 +528,7 @@ async function findAccount(ctx, id) {
 async function renderError(ctx, out, error) {
     const data = {
         dashboardOrigin: settings.dashboardOrigin(),
-        error
+        errorMessage: error.error_detail || 'Unknown error'
     };
 
     debug('renderError:', error);

src/oidc_templates/error.ejs

@@ -32,7 +32,7 @@
       <br/>
       <div class="row">
         <div class="col-md-12 text-center">
-          <%- Object.entries(error).map(([key, value]) => `<pre><strong>${key}</strong>: ${value}</pre>`).join('') %>
+          <%= errorMessage %>
         </div>
       </div>
     </div>