fix(api/configs): Ignore empty environment variables when loading config. (#5647)

api/configs/app_config.py

@@ -36,6 +36,7 @@ class DifyConfig(
         # read from dotenv format config file
         env_file='.env',
         env_file_encoding='utf-8',
+        env_ignore_empty=True,
 
         # ignore extra attributes
         extra='ignore',