v3.6: 优化 solon-server 不再默认输出 TEXT_PLAIN_UTF8_VALUE（允许空 content-type）

Author: noear

solon-jakarta-projects/solon-web/solon-web-servlet-jakarta/src/main/java/org/noear/solon/web/servlet/SolonServletHandler.java

@@ -44,7 +44,7 @@ protected boolean useLimitStream() {
     @Override
     protected void service(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
         SolonServletContext ctx = new SolonServletContext(request, response, useLimitStream());
-        ctx.contentType(MimeType.TEXT_PLAIN_UTF8_VALUE);
+        //ctx.contentType(MimeType.TEXT_PLAIN_UTF8_VALUE);
 
         preHandle(ctx);