Fixed problem when handler is None

coloredlogs/__init__.py

@@ -434,11 +434,12 @@ def install(level=None, **kw):
                 use_colors = terminal_supports_colors(stream)
         # Create a stream handler.
         # preserve any filters the current handler might have
-        preserved_filters = handler.filters
+        preserved_filters = handler.filters if handler else None
         handler = logging.StreamHandler(stream) if stream else StandardErrorHandler()
         handler.setLevel(level)
         # and add them back to the new handler
-        handler.filters = preserved_filters
+        if preserved_filters:
+            handler.filters = preserved_filters
         # Prepare the arguments to the formatter, allowing the caller to
         # customize the values of `fmt', `datefmt' and `style' as desired.
         formatter_options = dict(fmt=kw.get('fmt'), datefmt=kw.get('datefmt'))