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>

Author: dependabot-preview[bot]

requirements.txt

@@ -1,4 +1,4 @@
-Flask==1.1.1
+Flask==1.1.2
 Flask-WTF==0.14.2
 Jinja2==2.10.1
 MarkupSafe==1.1.1