Update dependency flask to v1.1.4

Author: renovate-bot

requirements.txt

@@ -1,7 +1,7 @@
 click==7.1.2; python_version >= "2.7" and python_full_version < "3.0.0" or python_full_version >= "3.5.0"
 ddtrace==0.44.0; (python_version >= "2.7" and python_full_version < "3.0.0") or (python_full_version >= "3.5.0")
 flask-sqlalchemy==2.4.4; (python_version >= "2.7" and python_full_version < "3.0.0") or (python_full_version >= "3.4.0")
-flask==1.1.2; (python_version >= "2.7" and python_full_version < "3.0.0") or (python_full_version >= "3.5.0")
+flask==1.1.4; (python_version >= "2.7" and python_full_version < "3.0.0") or (python_full_version >= "3.5.0")
 intervaltree==3.1.0; python_version >= "2.7" and python_full_version < "3.0.0" or python_full_version >= "3.5.0"
 itsdangerous==1.1.0; python_version >= "2.7" and python_full_version < "3.0.0" or python_full_version >= "3.5.0"
 jinja2==2.11.2; python_version >= "2.7" and python_full_version < "3.0.0" or python_full_version >= "3.5.0"