remove unused function

app/log/log.go

@@ -6,7 +6,6 @@ import (
 	"context"
 	"sync"
 
-	"v2ray.com/core/app"
 	"v2ray.com/core/app/log/internal"
 	"v2ray.com/core/common"
 	"v2ray.com/core/common/log"
@@ -102,14 +101,6 @@ func (g *Instance) Close() {
 	g.errorLogger = nil
 }
 
-func FromSpace(space app.Space) *Instance {
-	v := space.GetApplication((*Instance)(nil))
-	if logger, ok := v.(*Instance); ok && logger != nil {
-		return logger
-	}
-	return nil
-}
-
 func init() {
 	common.Must(common.RegisterConfig((*Config)(nil), func(ctx context.Context, config interface{}) (interface{}, error) {
 		return New(ctx, config.(*Config))