5794 Add reference to RFC 5903 to ike.config(4)

@@ -1193,5 +1193,9 @@
 Group. May 2003.
 .sp
 .LP
 Lepinksi, M. and Kent, S. \fIRFC 5114, Additional Diffie-Hellman Groups for Use
 with IETF Standards\fR. BBN Technologies, January 2008.
+.sp
+.LP
+Fu, D. and Solinas, J. \fIRFC 5903, Elliptic Curve Groups modulo a Prime (ECP
+Groups) for IKE and IKEv2\fR. NSA, June 2010.