Fix development server admin media URL
Fix development server admin media URL

This was broken by accident when fixing a related bug that broke
things in non-development mode (when I introduced MOUNT_POINT)


OSSystems/lava-server,OSSystems/lava-server,Linaro/lava-server,OSSystems/lava-server,Linaro/lava-server,Linaro/lava-server,Linaro/lava-server