map widget: start with normal zoomlevel

Commit 344d9765936 resulted in the start of Subsurface with a map of
the whole world. The user has to zoom in (assuming the case that the
first selected dive has a position), in evenry session. This is solved
by setting the zoomlevel at startup at the default value. Ok, this
results in a map of central London, UK, when starting Subsurface with
a dive without location, but is this as good as any map.

Signed-off-by: Jan Mulder <jlmulder@xs4all.nl>

mobile-widgets/qml/MapWidget.qml

@@ -25,7 +25,7 @@ Item {
 	Map {
 		id: map
 		anchors.fill: parent
-		zoomLevel: 1
+		zoomLevel: defaultZoomIn
 
 		property var mapType
 		readonly property var defaultCenter: QtPositioning.coordinate(0, 0)