fixup! Obsolete Transaction properties

Fix obsolete messages

Author: fredericDelaporte

src/NHibernate/IStatelessSession.cs

@@ -64,7 +64,7 @@ public partial interface IStatelessSession : IDisposable
 
 		/// <summary>Get the current NHibernate transaction.</summary>
 		// Since v5.3
-		[Obsolete("Use CurrentTransaction instead, and check for null.")]
+		[Obsolete("Use GetCurrentTransaction extension method instead, and check for null.")]
 		ITransaction Transaction { get; }
 
 		/// <summary>

src/NHibernate/Impl/AbstractSessionImpl.cs

@@ -38,7 +38,7 @@ public abstract partial class AbstractSessionImpl : ISessionImplementor
 
 		/// <summary>Get the current NHibernate transaction.</summary>
 		// Since v5.3
-		[Obsolete("Use CurrentTransaction instead, and check for null.")]
+		[Obsolete("Use GetCurrentTransaction extension method instead, and check for null.")]
 		public ITransaction Transaction => ConnectionManager.Transaction;
 
 		protected bool IsTransactionCoordinatorShared { get; }