fix import path for storage extension

Signed-off-by: Christian Richter <crichter@owncloud.com>

ocis/pkg/command/ocdav.go

@@ -1,9 +1,9 @@
 package command
 
 import (
+	"github.com/owncloud/ocis/extensions/storage/pkg/command"
 	"github.com/owncloud/ocis/ocis-pkg/config"
 	"github.com/owncloud/ocis/ocis/pkg/register"
-	"github.com/owncloud/ocis/storage/pkg/command"
 	"github.com/urfave/cli/v2"
 )