multi: add AutoCompact option to bolt backend

With this commit we thread the new AutoCompact flags all the way through
to the bolt backend.

channeldb/db.go

@@ -238,7 +238,13 @@ func Open(dbPath string, modifiers ...OptionModifier) (*DB, error) {
 		modifier(&opts)
 	}
 
-	backend, err := kvdb.GetBoltBackend(dbPath, dbName, opts.NoFreelistSync)
+	backend, err := kvdb.GetBoltBackend(&kvdb.BoltBackendConfig{
+		DBPath:            dbPath,
+		DBFileName:        dbName,
+		NoFreelistSync:    opts.NoFreelistSync,
+		AutoCompact:       opts.AutoCompact,
+		AutoCompactMinAge: opts.AutoCompactMinAge,
+	})
 	if err != nil {
 		return nil, err
 	}