Make sure time_ago_with_tooltip is using a Time object

Somehow this test existed on EE but not in CE, so it started failing
after a bad CE-to-EE merge.

app/helpers/application_helper.rb

@@ -205,7 +205,7 @@ module ApplicationHelper
   def time_ago_with_tooltip(time, placement: 'top', html_class: 'time_ago', skip_js: false)
     element = content_tag :time, time.to_s,
       class: "#{html_class} js-timeago js-timeago-pending",
-      datetime: time.getutc.iso8601,
+      datetime: time.to_time.getutc.iso8601,
       title: time.in_time_zone.to_s(:medium),
       data: { toggle: 'tooltip', placement: placement, container: 'body' }
 

spec/helpers/application_helper_spec.rb

@@ -285,6 +285,10 @@ describe ApplicationHelper do
     it 'allows the script tag to be excluded' do
       expect(element(skip_js: true)).not_to include 'script'
     end
+
+    it 'converts to Time' do
+      expect { helper.time_ago_with_tooltip(Date.today) }.not_to raise_error
+    end
   end
 
   describe 'render_markup' do