Fix distcheck

Missing file in Makefile.am

git-svn-id: svn://bind10.isc.org/svn/bind10/branches/trac408@3807 e5f2f494-b856-4b98-b285-d166d9295462

src/lib/nsas/Makefile.am

@@ -23,5 +23,6 @@ libnsas_la_SOURCES += zone_entry.cc zone_entry.h
 libnsas_la_SOURCES += fetchable.h
 libnsas_la_SOURCES += address_request_callback.h
 libnsas_la_SOURCES += resolver_interface.h
+libnsas_la_SOURCES += random_number_generator.h
 
 CLEANFILES = *.gcno *.gcda