Shorten tox job names for keystone.

We're running into failures on stable/newton:

https://review.openstack.org/#/c/423201/ which seems to be related to
the tox job name. To be safe lets reduce the names of these jobs.

Change-Id: I351f3f0992c6b9b13c19ab545e4c05b35b1b4d13
Depends-On: Ia803b95903005bbb318c9c96ba4e3b2f83f41c0b

tox.ini

@@ -124,7 +124,7 @@ commands =
     bash -c "{toxinidir}/tests/common/test-ansible-functional.sh"
 
 
-[testenv:uwsgi_apache]
+[testenv:uw_apache]
 deps =
     {[testenv:ansible]deps}
 setenv =
@@ -135,7 +135,7 @@ commands =
     bash -c "{toxinidir}/tests/common/test-ansible-functional.sh"
 
 
-[testenv:uwsgi_nginx]
+[testenv:uw_nginx]
 deps =
     {[testenv:ansible]deps}
 setenv =