Fix mongo example

Author: krinart

examples/mongodb.rs

@@ -41,7 +41,7 @@ async fn main(){
     let mongodb_params = to_secret_map(HashMap::from([
         (
             "connection_string".to_string(),
-            "mongodb://root:password@localhost:27017/mongo_db?authSource=admin&tls=true".to_string(),
+            "mongodb://root:password@localhost:27017/mongo_db?authSource=admin&tls=false".to_string(),
         ),
     ]));