Fix warden server test init

This did not work for python 3.9 and 3.10 (each for a different reason)
The context management of the cursor, seems to have been an undocumented feature
for at least six years.

warden_server/test_warden_server.py

@@ -412,7 +412,7 @@ def init_user():
     conn = None
     try:
         conn = my.connect(user='root', passwd=getpass.getpass('Enter MySQL Root password:'))
-        with conn as cur:   # Not a canonical connector implementation, for sure
+        with conn.cursor() as cur:
             cur.execute("GRANT SELECT, INSERT, UPDATE, CREATE, DELETE, DROP ON *.* TO %s@'localhost' IDENTIFIED BY %s", (USER, PASSWORD))
         conn.commit()
         print("DB User set up successfuly")