Set default value for NonceLength to 32 (#2970)

Author: mrsuciu

Stack/Opc.Ua.Core/Security/Certificates/Nonce.cs

@@ -611,7 +611,7 @@ protected Nonce(SerializationInfo info, StreamingContext context)
         #region Private Static Members
         private static readonly RandomNumberGenerator m_rng = RandomNumberGenerator.Create();
 
-        private static uint m_minNonceLength = 0;
+        private static uint m_minNonceLength = 32;
         #endregion
 
 #region IDisposable