Just assert for 'Hi' in generated mailer tests.

railties/lib/rails/generators/test_unit/mailer/templates/functional_test.rb

@@ -7,7 +7,7 @@ class <%= class_name %>Test < ActionMailer::TestCase
     assert_equal <%= action.to_s.humanize.inspect %>, mail.subject
     assert_equal ["to@example.org"], mail.to
     assert_equal ["from@example.com"], mail.from
-    assert_match "Hi, find me in app", mail.body.encoded
+    assert_match "Hi", mail.body.encoded
   end
 
 <% end -%>