ugps: Only convert lat and lon to negative after parsing

ugps: Only convert lat and lon to negative after parsing

This is a bugfix for package ugps.

Current code parses following GPRMC

$GPRMC,185834.0,A,2335.766399,S,04635.923564,W,0.0,,191017,0.0,E,A*20

as

position: -22.929440 -45.932056

with this fix it's being parsed correctly as

position: -23.596106 -46.598721

Signed-off-by: Giovani Milanez Espindola <gespindola@advantech-bb.com>
>From 092b311a3c8911ce9da3f913787b77397e88b4a8 Mon Sep 17 00:00:00 2001
From: Giovani Espindola <gespindola@advantech-bb.com>
Date: Thu, 19 Oct 2017 15:54:05 -0200
Subject: [PATCH] Only convert lat and lon to negative after parsing