core/manager: Make sure jobs statistics are not double after daemon-reload

We add n_installed_jobs and n_failed_jobs to our inner state after
deserialization. This is fine during daemon-reexec when we start with clear
Manager (and some jobs possibly queued before deserialization), however,
daemon-reload works with the same manager and adding the values would
effectively double the counters. Reset the counters before we deserialize and
add their values again.

src/core/manager.c

@@ -1234,6 +1234,8 @@ static void manager_clear_jobs_and_units(Manager *m) {
 
         m->n_on_console = 0;
         m->n_running_jobs = 0;
+        m->n_installed_jobs = 0;
+        m->n_failed_jobs = 0;
 }
 
 Manager* manager_free(Manager *m) {