Display multi-line commit message on commit diff page.

templates/repo/diff.tmpl

@@ -17,7 +17,7 @@
         <div class="panel panel-info panel-radius diff-head-box">
             <div class="panel-header">
                 <a class="pull-right btn btn-blue btn-header btn-medium btn-radius" rel="nofollow" href="{{.SourcePath}}">{{.i18n.Tr "repo.diff.browse_source"}}</a>
-                <h4>{{.Commit.Message}}</h4>
+                <h4 class="commit-message">{{.Commit.Message}}</h4>
             </div>
             <div class="panel-body">
                 <span class="pull-right">