minor dockerfile fix

Author: AkinAguda

Dockerfile

@@ -68,7 +68,7 @@ COPY --from=builder /work/Cargo.toml /app/
 
 ENV RUST_LOG="debug"
 ENV PORT=8080
-ENV LEPTOS_SITE_ADDR=0.0.0.0:\${PORT}
+ENV LEPTOS_SITE_ADDR=0.0.0.0:${PORT}
 ENV LEPTOS_SITE_ROOT=./site
 EXPOSE 8080