Added E flag (#217)

Added -E flag to use the set up environment.

run.sh

@@ -80,7 +80,7 @@ if [ "$1" = "import" ]; then
 
     #Import external data
     sudo chown -R renderer: /home/renderer/src
-    sudo -u renderer python3 /home/renderer/src/openstreetmap-carto/scripts/get-external-data.py -c /home/renderer/src/openstreetmap-carto/external-data.yml -D /home/renderer/src/openstreetmap-carto/data
+    sudo -E -u renderer python3 /home/renderer/src/openstreetmap-carto/scripts/get-external-data.py -c /home/renderer/src/openstreetmap-carto/external-data.yml -D /home/renderer/src/openstreetmap-carto/data
 
     # Register that data has changed for mod_tile caching purposes
     touch /var/lib/mod_tile/planet-import-complete