Fix Flatscreen/2D_Button example;

Hmmmm

examples/Flatscreen/2D_Button/conf.lua

@@ -0,0 +1,3 @@
+function lovr.conf(t)
+	t.modules.headset = false
+end

examples/Flatscreen/2D_Button/main.lua

@@ -30,5 +30,5 @@ function lovr.draw(pass)
   pass:plane(button.x, button.y, 0, button.w, button.h)
 
   pass:setColor(1, 1, 1)
-  pass:text('Click me!', button.x, button.y)
+  pass:text('Click me!', button.x, button.y, 0)
 end