contrib: fix makedistcheck with disabled systemd
contrib: fix makedistcheck with disabled systemd

EXTRA_DIST files need to be distributed, no matter if the systemd option
is configured or not.

Change-Id: I2e417f4c453987df1ac04f0ff41bf000da4b5c49

osmocom/osmo-trx,ttsou/osmo-trx,osmocom/osmo-trx,ttsou/osmo-trx,ttsou/osmo-trx,ttsou/osmo-trx,osmocom/osmo-trx,osmocom/osmo-trx