Fix ubuntu version

Author: Takahiro-Yoko

documentation/modules/exploit/linux/http/selenium_greed_chrome_rce_cve_2022_28108.md

@@ -9,7 +9,7 @@ The vulnerability affects:
 
 This module was successfully tested on:
 
-    * selenium/standalone-chrome:3.141.59 installed with Docker on Ubuntu 24.0.4
+    * selenium/standalone-chrome:3.141.59 installed with Docker on Ubuntu 20.0.4
 
 
 ### Installation