Switch github URLs to use https

Fixes #3415

Vendorfile

@@ -4,28 +4,28 @@ folder 'vendor/assets' do
   end
 
   folder 'leaflet' do
-    from 'git://github.com/aratcliffe/Leaflet.contextmenu.git', :tag => 'v1.5.1' do
+    from 'https://github.com/aratcliffe/Leaflet.contextmenu.git', :tag => 'v1.5.1' do
       file 'leaflet.contextmenu.js', 'dist/leaflet.contextmenu.js'
       file 'leaflet.contextmenu.css', 'dist/leaflet.contextmenu.css'
     end
 
-    from 'git://github.com/kajic/leaflet-locationfilter.git' do
+    from 'https://github.com/kajic/leaflet-locationfilter.git' do
       file 'leaflet.locationfilter.css', 'src/locationfilter.css'
       file 'leaflet.locationfilter.js', 'src/locationfilter.js'
       folder 'img', 'src/img'
     end
 
-    from 'git://github.com/jfirebaugh/leaflet-osm.git' do
+    from 'https://github.com/jfirebaugh/leaflet-osm.git' do
       file 'leaflet.osm.js', 'leaflet-osm.js'
     end
 
-    from 'git://github.com/jieter/Leaflet.encoded.git', :tag => '0.0.9' do
+    from 'https://github.com/jieter/Leaflet.encoded.git', :tag => '0.0.9' do
       file 'leaflet.polyline.js', 'Polyline.encoded.js'
     end
   end
 
   folder 'iD' do
-    from 'git://github.com/openstreetmap/iD', :branch => 'release' do
+    from 'https://github.com/openstreetmap/iD', :branch => 'release' do
       folder 'iD/data', 'dist/data'
       folder 'iD/img', 'dist/img'
       folder 'iD/locales', 'dist/locales'