Hi all,
I just want to say that I have solved the problem and I will try to explain what I did here. First, I changed the view to this:
<leaflet id="map_wandeling" class="superfill" tiles="tiles" ng-init="doMapInit()"></leaflet>
(Especially the ng-init is important here)
Then I changed the controller to have a function called doMapInit, with the following content:
$scope.doMapInit = function() {
angular.extend($scope, {
tiles: {
url: 'http://{s}.tile.opencyclemap.org/cycle/{z}/{x}/{y}.png'
},
defaults: {
scrollWheelZoom: false
}
});
leafletData.getMap('map_wandeling').then(function(map) {
$scope.map = map;
});
};
I hope this helps, it did work for me! Note that you need the Angular-Leaflet-plugin for this 
I think because I now use a specific “url = http://…”, leaflet knows that I am talking about external links and thus doesn’t change them to file://