Change += to = in last commit
diff --git a/tools/licenses.py b/tools/licenses.py
index 6fd1275..e4cdb8e 100755
--- a/tools/licenses.py
+++ b/tools/licenses.py
@@ -439,7 +439,7 @@
 
     file_template = open(os.path.join(templates_dir,
                                       'about_credits.tmpl'), 'rb').read()
-    template_contents += EvaluateTemplate(file_template,
+    template_contents = EvaluateTemplate(file_template,
                                           {'entries': '\n'.join(entries)},
                                           escape=False)