requests pulls in urllib3 2.x but that fails with an error

They say 1.26.x will be maintained for a while.  To fix, someone needs
to figure out what the exact problem is as shown in:
psf/requests#6443 (comment)

I suppose there will need to be some change related to the urllib 2.x
migration, but it is unclear to me which.  The usage of requests in
fdroid/sdkmanager is quite simple.
https://urllib3.readthedocs.io/en/latest/v2-migration-guide.html

setup.py

@@ -49,7 +49,7 @@ def run(self):
     entry_points={'console_scripts': ['sdkmanager=sdkmanager:main']},
     python_requires='>=3.5',
     cmdclass={'versioncheck': VersionCheckCommand},
-    install_requires=['argcomplete', 'requests > 2.12.2, != 2.18.0'],
+    install_requires=['argcomplete', 'requests > 2.12.2, != 2.18.0', 'urllib3<2'],
     extras_require={'test': ['defusedxml', 'requests-cache']},
     classifiers=[
         'Development Status :: 4 - Beta',