T326731 fix install path
Bug 326731
EVENTUTILITIES_LIB_DIR path had been updated in blubber, but not in the Makefile install target.
The latter was still pointing to ${HOME} instead of Docker's container workdir. This caused a test failure,
but the CI jobs was tagged as "allowed to fail". This change is required to bundle jars to all image variants (including production).
Now that we track a RELEASE version of wikimedia-eventutilities, tests should not be allowed to fail.