res_calendar: Specialized calendars depend on symbols of general calendar.

ASTERISK-27680

Change-Id: Ifb77912e424fe3710a025c18526fada673ec0b79

res/res_calendar_icalendar.c

@@ -21,6 +21,7 @@
  */
 
 /*** MODULEINFO
+	<depend>res_calendar</depend>
 	<depend>neon</depend>
 	<depend>ical</depend>
 	<support_level>extended</support_level>
@@ -541,4 +542,5 @@ AST_MODULE_INFO(ASTERISK_GPL_KEY, AST_MODFLAG_LOAD_ORDER, "Asterisk iCalendar .i
 	.load = load_module,
 	.unload = unload_module,
 	.load_pri = AST_MODPRI_DEVSTATE_PLUGIN,
+	.requires = "res_calendar",
 );