Update sqlite3.py to enable autocommit

as per saltstack #18152 
https://docs.python.org/2/library/sqlite3.html#sqlite3.Connection.isolation_level
addition of "isolation_level=None" to sqlite3.connect allows autocommit of "INSERT"
otherwise _connect would have to be called again with a con.commit()

salt/modules/sqlite3.py

@@ -23,7 +23,7 @@ def _connect(db=None):
     if db is None:
         return False
 
-    con = sqlite3.connect(db)
+    con = sqlite3.connect(db, isolation_level=None)
     cur = con.cursor()
     return cur