vici: Expose ike-update event

src/libcharon/plugins/vici/README.md

@@ -976,6 +976,22 @@ The _ike-rekey_ event is issued when an IKE_SA is rekeyed.
 		}
 	}
 
+### ike-update ###
+
+The _ike-update_ event is issued when the local or remote endpoint address of an
+IKE_SA is about to change (at least one address/port is different).
+
+	{
+		local-host = <new/current local IKE endpoint address>
+		local-port = <new/current local IKE endpoint port>
+		remote-host = <new/current remote IKE endpoint address>
+		remote-port = <new/current remote IKE endpoint port>
+		<IKE_SA config name> = {
+			<same data as in the list-sas event, but without child-sas section
+			 and listing the old addresses/ports>
+		}
+	}
+
 ### child-updown ###
 
 The _child-updown_ event is issued when a CHILD_SA is established or terminated.