Bump pyjwt from 2.1.0 to 2.4.0 in /jmclient

Bumps [pyjwt](https://github.com/jpadilla/pyjwt) from 2.1.0 to 2.4.0.
- [Release notes](https://github.com/jpadilla/pyjwt/releases)
- [Changelog](https://github.com/jpadilla/pyjwt/blob/master/CHANGELOG.rst)
- [Commits](https://github.com/jpadilla/pyjwt/compare/2.1.0...2.4.0)

---
updated-dependencies:
- dependency-name: pyjwt
  dependency-type: direct:production
...

Signed-off-by: dependabot[bot] <support@github.com>

jmclient/setup.py

@@ -11,6 +11,6 @@ setup(name='joinmarketclient',
       packages=['jmclient'],
       install_requires=['joinmarketbase==0.9.7dev', 'mnemonic', 'argon2_cffi',
                         'bencoder.pyx>=2.0.0', 'pyaes', 'klein==20.6.0',
-                        'pyjwt==2.1.0', 'autobahn==20.12.3'],
+                        'pyjwt==2.4.0', 'autobahn==20.12.3'],
       python_requires='>=3.6',
       zip_safe=False)