feat: 增加重置模型倍率功能 (close #62)

service/token_counter.go

@@ -30,7 +30,7 @@ func InitTokenEncoders() {
 	if err != nil {
 		common.FatalLog(fmt.Sprintf("failed to get gpt-4 token encoder: %s", err.Error()))
 	}
-	for model, _ := range common.DefaultModelRatio {
+	for model, _ := range common.GetDefaultModelRatioMap() {
 		if strings.HasPrefix(model, "gpt-3.5") {
 			tokenEncoderMap[model] = gpt35TokenEncoder
 		} else if strings.HasPrefix(model, "gpt-4") {