Update README.md

[ci skip]

Author: patrikjuvonen

README.md

@@ -11,7 +11,7 @@ See the [official wiki page](https://wiki.multitheftauto.com/wiki/PHP_SDK) for f
 
 ### Prerequisites
 
-This SDK requires PHP 7.3 or greater.
+This SDK requires PHP 7.4 or greater.
 
 ### HTTPlug client abstraction