Update sdlthread.inc version

Author: Free-Pascal-meets-SDL-Website

units/sdl2.pas

@@ -131,7 +131,7 @@ interface
 {$I sdlerror.inc}                // 2.0.14
 {$I sdlplatform.inc}             // 2.0.14
 {$I sdlpower.inc}                // 2.0.14
-{$I sdlthread.inc}               // 2.26.2
+{$I sdlthread.inc}               // 2.30.2
 {$I sdlatomic.inc}               // 2.0.20
 {$I sdlmutex.inc}                // 2.26.5
 {$I sdltimer.inc}                // 2.0.18