x11-wm/gamescope: unbreak fetch due to repo growth

fetch: https://github.com/ValveSoftware/gamescope/commit/a618ea074660.patch: size mismatch: expected 2589, actual 2591

-index 5a47ff840..bba9ec849 100644
+index 5a47ff8403..bba9ec8492 100644

(cherry picked from commit 414fb528d5e449cbb4e0a9d2a11571fbc85cee5f)