etc/mpv.conf: replace eye-cancer profile

While this was funny, gpu-next doesn't support --sharpen and it is now
the default VO, so replace it with something that actually works.

Author: guidocella

etc/mpv.conf

@@ -137,7 +137,8 @@
 # The options declared as part of profiles override global default settings,
 # but only take effect when the profile is active.
 
-# The following profile can be enabled on the command line with: --profile=eye-cancer
+# The following profile can be enabled on the command line with:
+# --profile=bright
 
-#[eye-cancer]
-#sharpen=5
+#[bright]
+#gamma=20