Fix gamma warning

[Philip Taylor]

Assertion failed: "SDL_SetGamma failed"
Location: GameSetup.cpp:142 (SetVideoMode)

18:01 <@Philip-> janwas: Should the warning about gamma be disabled, because it's a bit annoying and doesn't seem to be useful?
18:03 < janwas> Philip-: hm, that check has failed (in the intervening years, no one was able to find the underlying problem), so it can probably be commented out :) (preferably with a note that it sometimes fails, usually on multimon systems)

[philip]

(In [7410]) Disable visible warnings when gamma-setting fails. Fixes #480.

[Jan Wassenberg]

(In [7421]) fix nvidia multimon gamma issue ("if at first you fail, try again..") refs #480

[(none)]

Milestone OS Pre-Alpha 1 deleted