ensure trailing slash in federation portals ui and api links

app/helpers/federation_helper.rb

@@ -3,6 +3,8 @@ module FederationHelper
 
   def federated_portals
     $FEDERATED_PORTALS ||= LinkedData::Client.settings.federated_portals
+    normalize_portals($FEDERATED_PORTALS)
+    $FEDERATED_PORTALS
   end
 
   def internal_portal_config(id)
@@ -257,4 +259,11 @@ def most_referred_portal(ontology_submissions)
     portal_counts.max_by { |_, count| count }&.first
   end
 
+  def normalize_portals(portals)
+    portals.each do |_, portal|
+      portal[:ui] += "/" unless portal[:ui].end_with?("/")
+      portal[:api] += "/" unless portal[:api].end_with?("/")
+    end
+  end
+
 end