GREEN fix rubyforgood#4172 displays item name on invalid donation amo…

…unt edit

* direct call to render doesn't load @Items causing partial to be unable
  to match item IDs to item names, resulting in displaying numbers
* replace with redirect to edit

app/controllers/donations_controller.rb

@@ -84,7 +84,7 @@ def update
     redirect_to donations_path
   rescue => e
     flash[:alert] = "Error updating donation: #{e.message}"
-    render "edit"
+    redirect_back(fallback_location: edit_donation_path)
   end
 
   def destroy