feat: add conditional setting for HTTP headers in OpenRouter channel type

relay/channel/openai/adaptor.go

@@ -225,8 +225,12 @@ func (a *Adaptor) SetupRequestHeader(c *gin.Context, header *http.Header, info *
 		}
 	}
 	if info.ChannelType == constant.ChannelTypeOpenRouter {
-		header.Set("HTTP-Referer", "https://www.newapi.ai")
-		header.Set("X-OpenRouter-Title", "New API")
+		if header.Get("HTTP-Referer") == "" {
+			header.Set("HTTP-Referer", "https://www.newapi.ai")
+		}
+		if header.Get("X-OpenRouter-Title") == "" {
+			header.Set("X-OpenRouter-Title", "New API")
+		}
 	}
 	return nil
 }