Problem description

Be able to read public GCS files without providing credentials.

Steps/code to reproduce the problem

path = "gs://tensorflow-nightly/prod/tensorflow/release/ubuntu_16/gpu_py37_full/nightly_release/18/20190813-010608/github/tensorflow/pip_pkg/tf_nightly_gpu-1.15.0.dev20190813-cp37-cp37m-linux_x86_64.whl"

import smart_open
try:
    f = smart_open.s

Describe the bug
I have noticed that app-link URLs like: https://company.okta.com/home/amazon_aws/0obm6u4wyuVYgbLdJ0x7/172 cause parsing error in okta_auth_config.py at line 45 (version 0.4.4).
It is caused by an underscore character '_' that should be encoded prior verification like '%5F'.

Traceback (most recent call last):
  File "/Users/nowam1/Library/Python/3.7/bin/okta-awsc