[gnome-maps] gpxShapeLayer: Declare constructor correctly

[Marcus Lundblad <mlundblad src gnome org>]

commit 74b62fca1a29bcda6e0431aabe939177a26eb7d4
Author: Marcus Lundblad <ml update uu se>
Date:   Tue Feb 6 23:10:59 2018 +0100

    gpxShapeLayer: Declare constructor correctly
    
    This class is declared with GObject.registerClass()
    so the constructor needs to be defined as _init().
    Otherwise, the parent class instance isn't initialized
    correctly.

 src/gpxShapeLayer.js |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)
---
diff --git a/src/gpxShapeLayer.js b/src/gpxShapeLayer.js
index d257b7d..81d323b 100644
--- a/src/gpxShapeLayer.js
+++ b/src/gpxShapeLayer.js
@@ -27,7 +27,7 @@ const Domparser = imports.xmldom.domparser;
 var GpxShapeLayer = GObject.registerClass(
 class GpxShapeLayer extends ShapeLayer.ShapeLayer {
 
-    constructor(params) {
+    _init(params) {
         super.construct(params);
 
         this._mapSource = new GeoJSONSource.GeoJSONSource({