Update e2e readme wrt secure parameter used for minio client in mnist script

Author: abhijeet-dhumal

docs/e2e.md

@@ -130,3 +130,4 @@ Currently the SDK doesn't support tolerations, so e2e tests can't be executed on
     AWS_STORAGE_BUCKET=<storage-bucket-name>
     AWS_STORAGE_BUCKET_MNIST_DIR=<storage-bucket-MNIST-datasets-directory>
     ```
+    Note : When using the Python Minio client to connect to a minio storage bucket, the `AWS_DEFAULT_ENDPOINT` environment variable by default expects secure endpoint where user can use endpoint url with https/http prefix for autodetection of secure/insecure endpoint.

tests/e2e/mnist.py

@@ -154,9 +154,10 @@ def prepare_data(self):
             secret_key = os.environ.get("AWS_SECRET_ACCESS_KEY")
             bucket_name = os.environ.get("AWS_STORAGE_BUCKET")
 
+            # remove prefix if specified in storage bucket endpoint url
+            secure = True
             if endpoint.startswith("https://"):
                 endpoint = endpoint[len("https://") :]
-                secure = True
             elif endpoint.startswith("http://"):
                 endpoint = endpoint[len("http://") :]
                 secure = False