setup_debian.sh in vagrant-vbguest-0.3.2

- old
+ new

@@ -1,5 +1,5 @@
 #!/bin/bash
-apt-get install -y linux-headers-`uname -r` dkms
+apt-get install -y linux-headers-`uname -r` dkms || exit 1
 mount /tmp/VBoxGuestAdditions.iso -o loop /mnt
 /mnt/VBoxLinuxAdditions.run --nox11
 umount /mnt
\ No newline at end of file