settings: Remove global vibration strength modifier

This will be replaced in favor of per-player vibration strength modifiers.

src/core/settings.cpp

@@ -150,7 +150,6 @@ void RestoreGlobalState() {
     values.players.SetGlobal(true);
     values.use_docked_mode.SetGlobal(true);
     values.vibration_enabled.SetGlobal(true);
-    values.vibration_strength.SetGlobal(true);
     values.motion_enabled.SetGlobal(true);
 }