Refactor stumpless_open_local_wel_target function

Currently, there are two constructors for WEL target, `stumpless_open_local_wel_target` and `stumpless_open_remote_wel_target` which have the same code except for arguments to `new_wel_target` which is called inside both the constructors. In order to avoid code duplication, change the implementation of `stumpless_open_local_wel_target` to internally use `stumpless_open_remote_wel_target` with the appropriate arguments.