Bump idna from 2.8 to 2.9

Bumps [idna](https://github.com/kjd/idna) from 2.8 to 2.9.
- [Release notes](https://github.com/kjd/idna/releases)
- [Changelog](https://github.com/kjd/idna/blob/master/HISTORY.rst)
- [Commits](kjd/idna@v2.8...v2.9)

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

requirements.txt

@@ -4,7 +4,7 @@ Click==7.1.1 --hash=sha256:e345d143d80bf5ee7534056164e5e112ea5e22716bbb1ce727941
 Flask==1.1.1 --hash=sha256:45eb5a6fd193d6cf7e0cf5d8a5b31f83d5faae0293695626f539a823e93b13f6 --hash=sha256:13f9f196f330c7c2c5d7a5cf91af894110ca0215ac051b5844701f2bfd934d52
 Flask-Compress==1.4.0 --hash=sha256:468693f4ddd11ac6a41bca4eb5f94b071b763256d54136f77957cfee635badb3
 gunicorn==19.9.0 --hash=sha256:aa8e0b40b4157b36a5df5e599f45c9c76d6af43845ba3b3b0efe2c70473c2471
-idna==2.8 --hash=sha256:ea8b7f6188e6fa117537c3df7da9fc686d485087abf6ac197f9c46432f7e4a3c
+idna==2.9 --hash=sha256:a068a21ceac8a4d63dbfd964670474107f541babbd2250d61922f029858365fa --hash=sha256:7588d1c14ae4c77d74036e8c22ff447b26d0fde8f007354fd48a7814db15b7cb
 itsdangerous==1.1.0 --hash=sha256:b12271b2047cb23eeb98c8b5622e2e5c5e9abd9784a153e9d8ef9cb4dd09d749
 Jinja2==2.10 --hash=sha256:74c935a1b8bb9a3947c50a54766a969d4846290e1e788ea44c1392163723c3bd
 MarkupSafe==1.1.0 --hash=sha256:d9ac82be533394d341b41d78aca7ed0e0f4ba5a2231602e2f05aa87f25c51672 \