Fix crash with autoinstall on non-systemd env

On WSL and any system without systemd the server crashes becauses
the syslog id is always set (and never None) and systemd cat cannot
connect to the journal.
We cant set the id to None because the API expects a string, so the
check "is not None" is always true.

Co-authored-by: Didier Roche <didrocks@ubuntu.com>

subiquity/server/controllers/cmdlist.py

@@ -60,7 +60,7 @@ class CmdListController(NonInteractiveController):
             with context.child("command_{}".format(i), desc):
                 if isinstance(cmd, str):
                     cmd = ['sh', '-c', cmd]
-                if self.syslog_id is not None:
+                if self.syslog_id:
                     journal.send(
                         "  running " + desc, SYSLOG_IDENTIFIER=self.syslog_id)
                     cmd = [

system_setup/server/server.py

@@ -55,6 +55,9 @@ class SystemSetupServer(SubiquityServer):
 
     def __init__(self, opts, block_log_dir):
         super().__init__(opts, block_log_dir)
+        self.echo_syslog_id = ""
+        self.event_syslog_id = ""
+        self.log_syslog_id = ""
         if is_reconfigure(opts.dry_run):
             self.set_source_variant("wsl_configuration")