examples/deepzoom_server: Enable multithreading

Author: bgilbert

examples/deepzoom/deepzoom_server.py

@@ -156,4 +156,4 @@ def slugify(text, delim=u'-'):
         pass
     load_slide()
 
-    app.run(host=opts.host, port=opts.port)
+    app.run(host=opts.host, port=opts.port, threaded=True)