link to a journal diff no longer faulty on non english locale

* because of a faulty implementation, the link to the diff used to work only for the locale en. The reason for that was the usage of the label as part of the link. With this commit the key is used for the link which is always correct

lib/open_project/journal_formatter/diff.rb

@@ -4,21 +4,23 @@ class OpenProject::JournalFormatter::Diff < JournalFormatter::Base
   unloadable
 
   def render(key, values, no_html = false)
-    label = label(key)
-
-    render_ternary_detail_text(label, values.last, values.first, no_html)
+    render_ternary_detail_text(key, values.last, values.first, no_html)
   end
 
   private
 
-  def format_html_detail(label)
+  def label(key, no_html)
+    label = super key
+
+    no_html ?
+      label :
       content_tag('strong', label)
   end
 
-  def render_ternary_detail_text(label, value, old_value, no_html)
-    link = link(label, no_html)
+  def render_ternary_detail_text(key, value, old_value, no_html)
+    link = link(key, no_html)
 
-    label = format_html_detail(label) unless no_html
+    label = label(key, no_html)
 
     if value.blank?
       l(:text_journal_deleted_with_diff, :label => label, :link => link)
@@ -31,11 +33,11 @@ class OpenProject::JournalFormatter::Diff < JournalFormatter::Base
     end
   end
 
-  def link(label, no_html)
+  def link(key, no_html)
     url_attr = { :controller => 'journals',
                  :action => 'diff',
                  :id => @journal.id,
-                 :field => label.downcase,
+                 :field => key.downcase,
                  :only_path => false,
                  :protocol => Setting.protocol,
                  :host => Setting.host_name }