Fix unrelated comment

Dockerfile

@@ -4,7 +4,7 @@ FROM alpine:${ALPINE_VERSION}
 
 RUN apk add --no-cache git python3 python3-dev py3-pip py3-setuptools build-base
 
-# build wheels in first image
+# build wheels in a build stage
 ENV VIRTUAL_ENV /opt/venv
 ENV PATH ${VIRTUAL_ENV}/bin:${PATH}