4.2.1 bugfix release

server/src/main/resources/banner.txt

@@ -7,7 +7,7 @@
  |_|\_\ |_|\_\ |_|      |_| |_|  \___|     \/     |_|  \___|   \_/\_/
 
  => Spring Boot             ::  ${spring-boot.version}
- => kkFileView              ::  4.2.0
+ => kkFileView              ::  4.2.1
  => Home site               ::  https://kkview.cn
  => Github                  ::  https://github.com/kekingcn/kkFileView
  => Gitee                   ::  https://gitee.com/kekingcn/file-online-preview

server/src/main/resources/web/main/record.ftl

@@ -46,6 +46,16 @@
     <div class="page-header">
         <h1>版本发布记录</h1>
     </div>
+    <div class="panel panel-success">
+        <div class="panel-heading">
+            <h3 class="panel-title">2023年04月18日，v4.2.1 版本</h3>
+        </div>
+        <div class="panel-body">
+            <div>
+                1. 修复 dwg 等 CAD 类型文件报空指针的 bug<br>
+            </div>
+        </div>
+    </div>
     <div class="panel panel-success">
         <div class="panel-heading">
             <h3 class="panel-title">2023年04月13日，v4.2.0 版本</h3>