snapper: fails to check if snapshot is required

[asj]

On a non btrfs/ext4/LVM system, where snapshots aren't required during yum/dnf install, the snapper plugin is still being called to snapshot and it errors out as below..

Reproducer:
After installing the dnf snapper plugin

Run

dnf install
::
snapper: creating pre_snapshot failed: error.unknown_config: org.freedesktop.DBus.Error.Failed
::
dbus[23850]: arguments to dbus_connection_close() were incorrect, assertion "connection->generation == _dbus_current_generation" failed in file ../../dbus/dbus-connection.c line 2936.
This is normally a bug in some application using the D-Bus library.