build-unit-test: Remove objmgr workaround

There used to be a systemd dependency on the phosphor-objmgr
repo that required it to be built a special config flag.

Things build without it now, so remove it, as it was hampering
development in that repo.

Tested:  Ran build-unit-test-docker.sh and run-unit-test-docker.sh

Change-Id: Ie107ba4902fb205377789a614a325ea28f918e68
Signed-off-by: Matt Spinler <spinler@us.ibm.com>
diff --git a/build-unit-test-docker.sh b/build-unit-test-docker.sh
index c98e744..683cdb6 100755
--- a/build-unit-test-docker.sh
+++ b/build-unit-test-docker.sh
@@ -365,7 +365,7 @@
 RUN curl -L https://github.com/openbmc/phosphor-objmgr/archive/${PKG_REV['phosphor-objmgr']}.tar.gz | tar -xz && \
 cd phosphor-objmgr-* && \
 ./bootstrap.sh && \
-./configure ${CONFIGURE_FLAGS[@]} --enable-unpatched-systemd && \
+./configure ${CONFIGURE_FLAGS[@]} && \
 make -j$(nproc) && \
 make install