make diff file header html safe when file is renamed

app/views/projects/diffs/_file_header.html.haml

@@ -19,10 +19,10 @@
     - if diff_file.renamed_file?
       - old_path, new_path = mark_inline_diffs(diff_file.old_path, diff_file.new_path)
       %strong.file-title-name.has-tooltip{ data: { title: diff_file.old_path, container: 'body' } }
-        = old_path
+        != old_path
       →
       %strong.file-title-name.has-tooltip{ data: { title: diff_file.new_path, container: 'body' } }
-        = new_path
+        != new_path
     - else
       %strong.file-title-name.has-tooltip{ data: { title: diff_file.file_path, container: 'body' } }
         = diff_file.file_path