entry: remove duplicate hook for debug level

entry.go

diff --git a/entry.go b/entry.go
index 27aa967..c38898c 100644
--- a/entry.go
+++ b/entry.go
@@ -85,7 +85,6 @@
 func (entry *Entry) Debug(args ...interface{}) {
 	if entry.Logger.Level >= Debug {
 		entry.log("debug", Debug, fmt.Sprint(args...))
-		entry.Logger.Hooks.Fire(Debug, entry)
 	}
 }