make USE_SCREEN=False imply USE_SYSTEMD=True

In order to start making the transition in the gate make
USE_SCREEN=False also mean USE_SYSTEMD=True. We'll never actually
declare USE_SYSTEMD=True in the gate (as that doesn't exist for stable
branches), but this will let us roll over the existing transition.

We also have to install systemd-python 234 because we are recording
exception info in the journal, and all versions before that had a bug
in processing that.

Remove the somewhat pointless screen following journalctl commands. We
really don't want or need those, and they tend to build up over time.

Depends-On: I24513f5cbac2c34cf0130bf812ff2df6ad76657c

Change-Id: I6af6d1857effaf662a9d72bd394864934eacbe70
diff --git a/files/rpms/general b/files/rpms/general
index 106aa6a..1393d18 100644
--- a/files/rpms/general
+++ b/files/rpms/general
@@ -29,7 +29,7 @@
 python-devel
 redhat-rpm-config # missing dep for gcc hardening flags, see rhbz#1217376
 screen
-systemd-python
+systemd-devel # for systemd-python
 tar
 tcpdump
 unzip