Bump cryptography from 2.6.1 to 3.2 in /core/admin

Bumps [cryptography](https://github.com/pyca/cryptography) from 2.6.1 to 3.2.
- [Release notes](https://github.com/pyca/cryptography/releases)
- [Changelog](https://github.com/pyca/cryptography/blob/master/CHANGELOG.rst)
- [Commits](https://github.com/pyca/cryptography/compare/2.6.1...3.2)

Signed-off-by: dependabot[bot] <support@github.com>
(cherry picked from commit 54ccfdf975)

# Conflicts:
#	core/admin/requirements-prod.txt

core/admin/requirements-prod.txt

@@ -0,0 +1,52 @@
+alembic==1.0.10
+asn1crypto==0.24.0
+Babel==2.6.0
+bcrypt==3.1.6
+blinker==1.4
+cffi==1.12.3
+Click==7.0
+cryptography==3.2
+decorator==4.4.0
+dnspython==1.16.0
+dominate==2.3.5
+Flask==1.0.2
+Flask-Babel==0.12.2
+Flask-Bootstrap==3.3.7.1
+Flask-DebugToolbar==0.10.1
+Flask-Limiter==1.0.1
+Flask-Login==0.4.1
+Flask-Migrate==2.4.0
+Flask-Script==2.0.6
+Flask-SQLAlchemy==2.4.0
+Flask-WTF==0.14.2
+gunicorn==19.9.0
+idna==2.8
+infinity==1.4
+intervals==0.8.1
+itsdangerous==1.1.0
+Jinja2==2.10.1
+limits==1.3
+Mako==1.0.9
+MarkupSafe==1.1.1
+mysqlclient==1.4.2.post1
+passlib==1.7.1
+psycopg2==2.8.2
+pycparser==2.19
+pyOpenSSL==19.0.0
+python-dateutil==2.8.0
+python-editor==1.0.4
+pytz==2019.1
+PyYAML==5.1
+redis==3.2.1
+#alpine3:12 provides six==1.15.0
+#six==1.12.0
+socrate==0.1.1
+SQLAlchemy==1.3.3
+srslib==0.1.4
+tabulate==0.8.3
+tenacity==5.0.4
+validators==0.12.6
+visitor==0.1.3
+Werkzeug==0.15.5
+WTForms==2.2.1
+WTForms-Components==0.10.4