fix: Reloader choked on very old namespace modules.

Namespace modules created with old versions of setuptools did not conform to spec . Those are still around, unfortunately.

fixes #1455

bottle.py

@@ -3997,7 +3997,7 @@ def run(self):
         files = dict()
 
         for module in list(sys.modules.values()):
-            path = getattr(module, '__file__', '')
+            path = getattr(module, '__file__') or ''
             if path[-4:] in ('.pyo', '.pyc'): path = path[:-1]
             if path and exists(path): files[path] = mtime(path)