reduce idle wake-ups

no need to trigger original goroutine if data was not enough.

connection_reactor.go

@@ -90,7 +90,9 @@ func (c *connection) inputAck(n int) (err error) {
 	}
 	leftover := atomic.AddInt32(&c.waitReadSize, int32(-n))
 	err = c.inputBuffer.BookAck(n, leftover <= 0)
-	c.triggerRead()
+	if leftover <= 0 {
+		c.triggerRead()
+	}
 	c.onRequest()
 	return err
 }