modify links to pdf en/fr versions

src/content/blog/2018_02_08_liquidity_smart_contract_deploy_live_demo_on_tezos_alphanet_jfla2018.md

@@ -261,5 +261,5 @@ The call should also succeed. When we examine the contract, we can now see that
 
 We have seen how to compile, deploy, call and examine Liquidity contracts on the Tezos alphanet using our online editor. Experiment with your own contracts and let us know how that works for you!
 
-- Slides in [English](/wp-content/uploads/2018/02/liquidity_slides.en_.pdf)
-- and [French](/wp-content/uploads/2018/02/liquidity_slides.pdf)
+- Slides in [English](https://files.ocamlpro.com/pub/liquidity_slides.en_.pdf)
+- and [French](https://files.ocamlpro.com/pub/liquidity_slides.pdf)