Merge pull request #5424 from matrix-org/erikj/change_password_reset_links

changelog.d/5424.misc

synapse/app/homeserver.py

synapse/push/mailer.py

synapse/python_dependencies.py

synapse/res/templates/password_reset_success.html

synapse/rest/client/v2_alpha/account.py

tests/push/test_email.py

tests/push/test_http.py

tests/rest/client/test_consent.py

tests/rest/client/v2_alpha/test_account.py

tests/rest/client/v2_alpha/test_register.py

tests/unittest.py