Bump flask from 1.1.1 to 1.1.2

Bumps [flask](https://github.com/pallets/flask) from 1.1.1 to 1.1.2.
- [Release notes](https://github.com/pallets/flask/releases)
- [Changelog](https://github.com/pallets/flask/blob/master/CHANGES.rst)
- [Commits](pallets/flask@1.1.1...1.1.2)

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

requirements.txt

@@ -1,5 +1,5 @@
 click==7.0
-Flask==1.1.1
+Flask==1.1.2
 itsdangerous==1.1.0
 Jinja2==2.10.3
 MarkupSafe==1.1.1