rm doubling

vtest/source/app.d

@@ -159,10 +159,10 @@ string get_all_cities(){
 void test_pg_conn_driver_queries(){
   
   client.pickConnection( (scope conn){
-    conn.prepareEx("get_city_by_id", "SELECT id, name, population FROM test WHERE id = $1"); // get_city_by_id
     QueryParams params; // https://github.com/denizzzka/dpq2/blob/master/src/dpq2/args.d#L15
     params.preparedStatementName = "get_city_by_id";
     params.argsVariadic(3); // https://github.com/denizzzka/dpq2/blob/master/example/example.d#L42  // https://github.com/denizzzka/dpq2/blob/master/src/dpq2/query.d#L336 // https://github.com/denizzzka/vibe.d.db.postgresql/blob/master/source/vibe/db/postgresql/package.d#L423
+    conn.prepareEx(params.preparedStatementName, "SELECT id, name, population FROM test WHERE id = $1"); // get_city_by_id
     auto result1 = conn.execPrepared(params);
     
     writeln("id: ", result1[0]["id"].as!PGinteger);