Fixes to Dockerfile

There was premature optimizations were we assumed we could rename the
workdir to luanti... but the game still uses minetest as workdir.

luanti/Dockerfile

@@ -25,19 +25,20 @@ RUN chdir minetest && \
 
 from debian:buster-slim as final
 
-WORKDIR /luanti
+WORKDIR /minetest
 
 RUN apt-get update && \
     apt-get install -y \
         libsqlite3-0 libcc1-0 libgmpxx4ldbl \
         librtmp1 libcurl3-gnutls libzstd-dev \
         libjsoncpp-dev libluajit-5.1 gettext \
+        libatomic1 \
     && apt-get clean && rm -rf /var/lib/apt/lists/*
 
-COPY --from=builder /minetest/minetest/bin/luantiserver /luanti/bin/server
+COPY --from=builder /minetest/minetest/bin/luantiserver /minetest/bin/server
 
-COPY --from=builder /minetest/minetest/textures /luanti/textures
-COPY --from=builder /minetest/minetest/builtin /luanti/builtin
+COPY --from=builder /minetest/minetest/textures /minetest/textures
+COPY --from=builder /minetest/minetest/builtin /minetest/builtin
 
 EXPOSE 30000
 #EXPOSE 8080