improve readme

README.md

@@ -33,8 +33,6 @@ There are also proof-of-concept ports of this script that only support basic RES
     - SQL Server 2012 or higher (2017 for Linux support)
     - SQLite 3.16 or higher (spatial features NOT supported)
 
-Recommended operating system: Ubuntu 20.04 or Debian 10
-
 ## Installation
 
 This is a single file application! Upload "`api.php`" somewhere and enjoy!