only update links if there's a message ID

lib/postal/fast_server/interface.rb

@@ -74,9 +74,11 @@ module Postal
           if message_db = get_message_db_from_server_token(server_token)
             if link = message_db.select(:links, :where => {:token => link_token}, :limit => 1).first
               time = Time.now.to_f
-              message_db.update(:messages, {:clicked => time}, :where => {:id => link['message_id']})
-              message_db.insert(:clicks, {:message_id => link['message_id'], :link_id => link['id'], :ip_address => request.ip, :user_agent => request.user_agent, :timestamp => time})
-              SendWebhookJob.queue(:main, :server_id => message_db.server_id, :event => 'MessageLinkClicked', :payload => {:_message => link['message_id'], :url => link['url'], :token => link['token'], :ip_address => request.ip, :user_agent => request.user_agent})
+              if link['message_id']
+                message_db.update(:messages, {:clicked => time}, :where => {:id => link['message_id']})
+                message_db.insert(:clicks, {:message_id => link['message_id'], :link_id => link['id'], :ip_address => request.ip, :user_agent => request.user_agent, :timestamp => time})
+                SendWebhookJob.queue(:main, :server_id => message_db.server_id, :event => 'MessageLinkClicked', :payload => {:_message => link['message_id'], :url => link['url'], :token => link['token'], :ip_address => request.ip, :user_agent => request.user_agent})
+              end
               return [307, {'Location' => link['url']}, ["Redirected to: #{link['url']}"]]
             else
               return [404, {}, ['Link not found']]