Addition to #31

Changes:
  * The value detection of "MINIO_USE_HTTPS" was faulty. False values were treated incorrectly.
  * Updated the docstring

django_minio_backend/models.py

@@ -419,7 +419,7 @@ def validate_settings(self):
         """
         validate_settings raises a ConfigurationError exception when one of the following conditions is met:
           * Neither MINIO_PRIVATE_BUCKETS nor MINIO_PUBLIC_BUCKETS have been declared and configured with at least 1 bucket
-          * A mandatory parameter (ENDPOINT, ACCESS_KEY, SECRET_KEY or USE_HTTP) hasn't been declared and configured properly
+          * A mandatory parameter (MINIO_ENDPOINT, MINIO_ACCESS_KEY, MINIO_SECRET_KEY or MINIO_USE_HTTPS) hasn't been declared and configured properly
         """
         # minimum 1 bucket has to be declared
         if not (get_setting("MINIO_PRIVATE_BUCKETS") or get_setting("MINIO_PUBLIC_BUCKETS")):