Adds support for multiselect custom fields (#1189).

git-svn-id: svn+ssh://rubyforge.org/var/svn/redmine/trunk@8721 e93f8b46-1217-0410-a6f0-8f06a7374b81

app/views/mailer/issue_edit.text.erb

@@ -1,7 +1,7 @@
 <%= l(:text_issue_updated, :id => "##{@issue.id}", :author => @journal.user) %>
 
-<% for detail in @journal.details -%>
-<%= show_detail(detail, true) %>
+<% details_to_strings(@journal.details, true).each do |string| -%>
+<%= string %>
 <% end -%>
 
 <%= @journal.notes if @journal.notes? %>