scene/boost: use the included input manager

sonic-boost.love/scenes/subgame/sonic-boost/controller/characters.lua

@@ -100,7 +100,7 @@ function Player:new(manager, playerid, character, rail)
 end
 
 function Player:getKeys()
-  return core.input.keys
+  return self.controller.keys
 end
 
 function Player:wrapActor()

sonic-boost.love/scenes/subgame/sonic-boost/init.lua

@@ -110,7 +110,7 @@ function BoostLevel:update(dt)
     --self.pausemenu:update(dt)
   end
 
-  if core.input.keys["start"].isPressed then
+  if self.keys["start"].isPressed then
     self.pause = (self.pause == false)
   end
 end