Raise alerts when enforcing IKE_SA unique policy

src/libcharon/bus/bus.h

@@ -111,6 +111,10 @@ enum alert_t {
 	ALERT_PROPOSAL_MISMATCH_IKE,
 	/** CHILD proposals do not match, argument is linked_list_t of proposal_t */
 	ALERT_PROPOSAL_MISMATCH_CHILD,
+	/** IKE_SA deleted because of "replace" unique policy, no argument */
+	ALERT_UNIQUE_REPLACE,
+	/** IKE_SA deleted because of "keep" unique policy, no arguement */
+	ALERT_UNIQUE_KEEP,
 };
 
 /**