Ignore a wider range of values for config_path

We were previously checking only for `None`, but it's probably
beneficial to ignore anything falsey. Change as suggested in code
review.

Signed-off-by: Ed Smith <[email protected]>

Author: eds-collabora

kernelci/config/__init__.py

@@ -168,7 +168,7 @@ def load(config_path):
     unified file
 
     """
-    if config_path is None:
+    if not config_path:
         return {}
     data = load_yaml(config_path)
     return from_data(data)