fix osm.earth bug

Author: gwaldron

tests/osm.earth

@@ -18,14 +18,14 @@ osgEarth Sample - OpenStreetMap Features
 
     <xi:include href="osm_buildings.xml" nvgl="true" open="false" name="FMG Buildings (NVGL)"/>
 
-    <XYZModel name="Freshly Baked Buildings (GL3)" open="false">
+    <XYZModel name="Freshly Baked Buildings (GL3)" nvgl="false" open="false">
         <url>https://pelican-public.s3.amazonaws.com/buildings_mak/{z}/{x}/{y}.osgb</url>
         <min_level>14</min_level>
         <max_level>14</max_level>
         <profile>spherical-mercator</profile>
     </XYZModel>
 
-    <XYZModel name="Freshly Baked Buildings (NVGL)" open="false">
+    <XYZModel name="Freshly Baked Buildings (NVGL)" nvgl="true" open="false">
         <url>https://pelican-public.s3.amazonaws.com/buildings_mak/{z}/{x}/{y}.osgb</url>
         <min_level>14</min_level>
         <max_level>14</max_level>