restore backup: don't automatically unmount an ehdd drive

ehdd/shutdown.sh

@@ -22,14 +22,19 @@ if [ -s /etc/mailinabox.conf ]; then
     systemctl stop miabldap-capture
 fi
 
-ehdd/umount.sh
-code=$?
-tries=1
-while [ $code -eq 2 -a $tries -le 3 ]; do
-    echo "Trying again in 10 seconds..."
-    sleep 10
+if [ "$1" != "--no-umount" ]; then
     ehdd/umount.sh
     code=$?
-    let tries+=1
-done
+    tries=1
+    while [ $code -eq 2 -a $tries -le 3 ]; do
+        echo "Trying again in 10 seconds..."
+        sleep 10
+        ehdd/umount.sh
+        code=$?
+        let tries+=1
+    done
+else
+    code=0
+fi
+
 exit $code