Update dependency Flask-SQLAlchemy to v2.3.2

Author: renovate-bot

requirements.txt

@@ -5,7 +5,7 @@ click==6.7
 Flask==0.12.1
 Flask-Migrate==2.0.4
 Flask-Script==2.0.6
-Flask-SQLAlchemy==2.2
+Flask-SQLAlchemy==2.3.2
 idna==2.6
 ipfsapi==0.4.2.post1
 itsdangerous==0.24