更新 'common.sh'

common.sh

@@ -200,7 +200,7 @@ function set_sources_update(){
 	chroot $mount_dir /bin/bash -c "echo 'deb $MIRRORS $DISTRIBUTION-backports main restricted universe multiverse' >> /etc/apt/sources.list"
 	chroot $mount_dir /usr/bin/apt-get -q update
 	chroot $mount_dir /usr/bin/apt-get -q -y -o DPkg::Options::=--force-confnew dist-upgrade
-	chroot $mount_dir /usr/bin/apt-get -q -y install wget apt-transport-https
+	chroot $mount_dir /usr/bin/apt-get -q -y install wget apt-transport-https gnupg2
 
 	# ubports repo
 	chroot $mount_dir wget http://repo.ubports.com/keyring.gpg