clarify breeze initialize virtualenv instructions (apache#9319)

* you need to activate virtualenv, not enter breeze, before running the command

LOCAL_VIRTUALENV.rst

@@ -141,7 +141,7 @@ You can solve the problem by:
 
 Note that if you have the Breeze development environment installed, the ``breeze``
 script can automate initializing the created virtualenv (steps 2 and 3).
-Simply enter the Breeze environment by using ``workon`` and, once you are in it, run:
+Activate your virtualenv, e.g. by using ``workon``, and once you are in it, run:
 
 .. code-block:: bash