use a random secret key (#3971)

Author: lum1n0us

tests/fuzz/wasm-mutator-fuzz/server/app/main.py

@@ -56,7 +56,7 @@
 app.config['SQLALCHEMY_TRACK_MODIFICATIONS'] = False
 
 
-app.secret_key = "hwhefsewljfejrlesjfl"
+app.secret_key = os.urandom(12).hex()
 
 db = SQLAlchemy(app)