improve consistency in Dockerfile CMD

remove /venv/bin as it's redundant and inconsistent with the earlier
versions of the Dockerfile in the chapter

Author: Xronophobe

chapter_09_docker.asciidoc

@@ -1313,9 +1313,12 @@ If you try it, you'll find it certainly fixes the problem:
 WORKDIR /src
 
 RUN python manage.py migrate --noinput  <1>
-CMD /venv/bin/python manage.py runserver
+CMD python manage.py runserver
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+// CSANAD:  I prefer specifying the path (/venv/bin/python) too, but we already set the PATH to in-
+//          clude /venv/bin and also, we haven't been using this explicit path in the Dockerfile.
+// So, for the sake of consistency, I suggest removing it here as well.
 
 <1> We run `migrate` using the `--noinput` argument to suppress any little "are you sure" prompts.
 
@@ -1363,7 +1366,7 @@ First let's revert our change:
 [...]
 WORKDIR /src
 
-CMD /venv/bin/python manage.py runserver
+CMD python manage.py runserver
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 ====