merge test_time_format tests from duplicate names

/home/travis/.rvm/rubies/ruby-2.1.5/lib/ruby/2.1.0/test/unit/testcase.rb:28:in
`method_added' : test/unit warning: method
Redmine::I18nTest#test_time_format is redefined (StandardWarning)

test/unit/lib/redmine/i18n_test.rb

@@ -84,6 +84,13 @@ class Redmine::I18nTest < ActiveSupport::TestCase
         assert_equal '15:45', format_time(now, false)
       end
     end
+
+    with_settings time_format: '%H %M' do
+      with_settings date_format: '%d %m %Y' do
+        assert_equal now.strftime('%d %m %Y %H %M'), format_time(now)
+        assert_equal now.strftime('%H %M'), format_time(now, false)
+      end
+    end
   end
 
   def test_time_format_default
@@ -102,17 +109,6 @@ class Redmine::I18nTest < ActiveSupport::TestCase
     end
   end
 
-  def test_time_format
-    set_language_if_valid 'en'
-    now = Time.now
-    with_settings :time_format => '%H %M' do
-      with_settings :date_format => '%d %m %Y' do
-        assert_equal now.strftime('%d %m %Y %H %M'), format_time(now)
-        assert_equal now.strftime('%H %M'), format_time(now, false)
-      end
-    end
-  end
-
   def test_utc_time_format
     set_language_if_valid 'en'
     now = Time.now