FIX sftp unlink path (#767)

auto_backup/__manifest__.py

@@ -7,7 +7,7 @@
 {
     "name": "Database Auto-Backup",
     "summary": "Backups database",
-    "version": "10.0.1.0.1",
+    "version": "10.0.1.0.2",
     "author": (
         "Yenthe Van Ginneken, "
         "Agile Business Group, "

auto_backup/models/db_backup.py

@@ -232,7 +232,7 @@ class DbBackup(models.Model):
                         for name in remote.listdir(rec.folder):
                             if (name.endswith(".dump.zip") and
                                     os.path.basename(name) < oldest):
-                                remote.unlink(name)
+                                remote.unlink('%s/%s' % (rec.folder, name))
 
     @api.multi
     @contextmanager