Correct a typo that was keeping Skia from compiling.

For example:
https://logs.chromium.org/logs/skia/5948b4721f002c11/+/steps/gn_gen/0/stdout.
More specifically:
https://logs.chromium.org/logs/skia/5948b4721f002c11/+/steps/gn_gen/0/stdout.

Bug crept in on
https://chromium-review.googlesource.com/c/angle/angle/+/3487449.

Bug: angleproject:7061
Change-Id: I6bae23375505aa714733033f5b84c1b3c8c421f9
Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/3488558
Reviewed-by: Jamie Madill <jmadill@chromium.org>
Commit-Queue: Jamie Madill <jmadill@chromium.org>

gni/angle.gni

@@ -52,7 +52,7 @@ if (angle_has_build) {
     build_with_chromium = false
     dcheck_always_on = false
     angle_use_x11 = (is_linux || is_chromeos) && !is_ggp
-    angle_use_wayland = is_linux && !is_gpp
+    angle_use_wayland = is_linux && !is_ggp
     use_ozone = false
     ozone_platform_gbm = false
     ozone_platform_wayland = false