Merge pull request PlatONnetwork#311 from WeiLoy/patch-61

修改下载链接的版本号

Author: biganxin

docs/成为主网验证节点.md

@@ -79,7 +79,7 @@ Ubuntu 22.04：
 
 ```bash
 sudo wget https://download.platon.network/platon/platon/ubuntu22.04/1.4.4/platon -O /usr/bin/platon
-sudo wget https://download.platon.network/platon/platon/ubuntu22.04/1.4.2/platonkey -O /usr/bin/platonkey
+sudo wget https://download.platon.network/platon/platon/ubuntu22.04/1.4.4/platonkey -O /usr/bin/platonkey
 ```
 
 ```bash