perf: set header can use For Qs (#562)

set header can use For Qs

Author: yirius

src/utils/http/axios/Axios.ts

@@ -155,7 +155,7 @@ export class VAxios {
 
   // support form-data
   supportFormData(config: AxiosRequestConfig) {
-    const headers = config.headers;
+    const headers = config.headers || this.options.headers;
     const contentType = headers?.['Content-Type'] || headers?.['content-type'];
 
     if (