operations-apache-config: Add /usr/local/apache/conf/ to filter pattern

The sed is stripping the qualified path for config files so that file
references point to the Jenkins workspace working directory rather than an
absolute filesystem path. Ia63c3f182 updates the canonical location of the
files (resolving a symlink reference, in effect), and thus breaks the tests.

Change-Id: I859f23cb7994d66d6041b21ff64b6fb38638086e