Fix build break in Release (#1248)

Author: Rob-Hague

src/Renci.SshNet/Abstractions/DiagnosticAbstraction.cs

@@ -9,12 +9,14 @@ namespace Renci.SshNet.Abstractions
     [EditorBrowsable(EditorBrowsableState.Never)]
     public static class DiagnosticAbstraction
     {
-#if DEBUG
         /// <summary>
         /// The <see cref="TraceSource"/> instance used by SSH.NET.
         /// </summary>
         /// <remarks>
         /// <para>
+        /// Currently, the library only traces events when compiled in Debug mode.
+        /// </para>
+        /// <para>
         /// Configuration on .NET Core must be done programmatically, e.g.
         /// <code>
         /// DiagnosticAbstraction.Source.Switch = new SourceSwitch("sourceSwitch", "Verbose");
@@ -49,7 +51,6 @@ public static class DiagnosticAbstraction
         /// </para>
         /// </remarks>
         public static readonly TraceSource Source = new TraceSource("SshNet.Logging");
-#endif
 
         /// <summary>
         /// Logs a message to <see cref="Source"/> at the <see cref="TraceEventType.Verbose"/>