fix docker build (#734)

docker/Dockerfile

@@ -1,6 +1,7 @@
 FROM alpine:edge AS builder
 RUN apk add -u crystal shards libc-dev \
-    yaml-dev libxml2-dev sqlite-dev sqlite-static zlib-dev openssl-dev
+    yaml-dev libxml2-dev sqlite-dev zlib-dev openssl-dev \
+    sqlite-static zlib-static openssl-libs-static
 WORKDIR /invidious
 COPY ./shard.yml ./shard.yml
 RUN shards update && shards install