error handler: increase font size slightly.

The new default font plus better kerning made the old size too small compared to 11.4.

src/modules/love/callbacks.lua

@@ -238,8 +238,7 @@ function love.errhand(msg)
 	if love.audio then love.audio.stop() end
 
 	love.graphics.reset()
-	local font = love.graphics.newFont(14)
-	love.graphics.setFont(font)
+	love.graphics.setFont(love.graphics.newFont(15))
 
 	love.graphics.setColor(1, 1, 1)