remove unused header

Author: erh

src/mongo/db/jsobj.cpp

@@ -30,7 +30,6 @@
 #include "mongo/bson/util/atomic_int.h"
 #include "mongo/db/jsobjmanipulator.h"
 #include "mongo/db/json.h"
-#include "mongo/db/nonce.h"
 #include "mongo/platform/float_utils.h"
 #include "mongo/util/base64.h"
 #include "mongo/util/embedded_builder.h"