KDE test: Bump kdm start timeout

Hopefully this will fix random failures like
http://hydra.nixos.org/build/36249079.

+8
+8
nixos/modules/testing/test-instrumentation.nix
··· 115 116 services.xserver.displayManager.logToJournal = true; 117 118 }; 119 120 }
··· 115 116 services.xserver.displayManager.logToJournal = true; 117 118 + # Bump kdm's X server start timeout to account for heavily loaded 119 + # VM host systems. 120 + services.xserver.displayManager.kdm.extraConfig = 121 + '' 122 + [X-:*-Core] 123 + ServerTimeout=240 124 + ''; 125 + 126 }; 127 128 }