Fix Lines json key bug (#217)

Co-authored-by: ke.like <ke.like@alibaba-inc.com>

model.go

@@ -13,7 +13,7 @@ type GetLogRequest struct {
 	From       int64  `json:"from"`  // unix time, eg time.Now().Unix() - 900
 	To         int64  `json:"to"`    // unix time, eg time.Now().Unix()
 	Topic      string `json:"topic"` // @note topic is not used anymore, use __topic__ : xxx in query instead
-	Lines      int64  `json:"lines"` // max 100; offset, lines and reverse is ignored when use SQL in query
+	Lines      int64  `json:"line"`  // max 100; offset, lines and reverse is ignored when use SQL in query
 	Offset     int64  `json:"offset"`
 	Reverse    bool   `json:"reverse"`
 	Query      string `json:"query"`