Configuration variable for system events

After user acknowledgement a system event is deleted from the event queue.
The configuration variable determines whether it is turned into an appointment
(for later inspection) or not.

Signed-off-by: Lukas Fleischer <lfleischer@calcurse.org>

src/vars.c

@@ -124,6 +124,7 @@ void vars_init(void)
 	conf.auto_save = 1;
 	conf.auto_gc = 0;
 	conf.periodic_save = 0;
+	conf.systemevents = 1;
 	conf.default_panel = CAL;
 	conf.compact_panels = 0;
 	conf.system_dialogs = 1;