fix useradd

tools/build_uec.sh

@@ -194,7 +194,7 @@ if [ -e ~/.ssh/id_rsa.pub ]; then
     PUB_KEY=`cat  ~/.ssh/id_rsa.pub`
     cat >> $vm_dir/uec/user-data<<EOF
 mkdir -p /opt/stack
-useradd stack -s /bin/bash -d /opt/stack -G libvirtd || true
+useradd -U -G sudo -s /bin/bash -d /opt/stack -m stack
 echo stack:pass | chpasswd
 mkdir -p /opt/stack/.ssh
 echo "$PUB_KEY" > /opt/stack/.ssh/authorized_keys