chore(deps): bump wtforms from 2.2.1 to 2.3.1

Bumps [wtforms](https://github.com/wtforms/wtforms) from 2.2.1 to 2.3.1.
- [Release notes](https://github.com/wtforms/wtforms/releases)
- [Changelog](https://github.com/wtforms/wtforms/blob/2.3.1/CHANGES.rst)
- [Commits](pallets-eco/wtforms@2.2.1...2.3.1)

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

Author: dependabot-preview[bot]

requirements/common.txt

@@ -47,7 +47,7 @@ diff-match-patch==20181111
 blinker==1.4
 envparse==0.2
 git+https://github.com/fossasia/flask-rest-jsonapi@0.12.6.2
-wtforms==2.2.1
+wtforms==2.3.1
 flask-admin==1.5.6
 google-compute-engine==2.8
 factory_boy==2.12