moved parameter_binder from member to parameter to bind, execute and fetch methods

backends/postgres/src/postgres_parameter_binder.cpp

@@ -53,7 +53,7 @@ postgres_parameter_binder::bind_data::bind_data(const size_t size)
 , formats(size)
 {}
 
-postgres_parameter_binder::postgres_parameter_binder(size_t size)
+postgres_parameter_binder::postgres_parameter_binder(const size_t size)
 : bind_data_(size)
 {}