chore: update docker build url

Author: mydearxym

deploy/production/Dockerfile

@@ -13,8 +13,8 @@ RUN apk add tzdata --force-broken-world
 RUN ln -sf /usr/share/zoneinfo/Asia/Shanghai /etc/localtime && echo "Asia/Shanghai" > /etc/timezone
 
 ADD api_server.tar.gz /root/api_server
-RUN mix hex.config mirror_url https://hexpm.upyun.com
-# RUN mix hex.config mirror_url https://cdn.jsdelivr.net/hex
+# RUN mix hex.config mirror_url https://hexpm.upyun.com
+RUN mix hex.config mirror_url https://cdn.jsdelivr.net/hex
 
 RUN cd /root/api_server && MIX_ENV=prod mix deps.get --only prod && MIX_ENV=prod mix compile