fix debian-bash-upgrade

install.sh

@@ -39,8 +39,10 @@ function install_host() {
         echo "--------------------------------"
         echo "debian-bash has been deprecated!"
         echo "--------------------------------"
- 
+        
         read -rn1 -p 'Would you like to migrate to the new project named `miaou-bash`, (yN)?' answer       
+        [[ -z "$PS1" ]] && answer='y'
+        
         if [[ "$answer" == 'y' ]];then
             pushd /tmp
             pushd /opt/debian-bash