UI: In the LaunchTracerDialog, only enable the Steam launcher option if steamlauncher.sh exists
UI: In the LaunchTracerDialog, only enable the Steam launcher option if steamlauncher.sh exists

bclemetsonblizzard/vogl,ValveSoftware/vogl,bclemetsonblizzard/vogl,bclemetsonblizzard/vogl,kingtaurus/vogl,kingtaurus/vogl,bclemetsonblizzard/vogl,ValveSoftware/vogl,kingtaurus/vogl,ValveSoftware/vogl,kingtaurus/vogl,ValveSoftware/vogl,bclemetsonblizzard/vogl