Address comments

Author: CristianAmbrosini

rules/S6670/vbnet/rule.adoc

@@ -3,7 +3,7 @@ include::../why-dotnet.adoc[]
 [source,vbnet,diff-id=1,diff-type=noncompliant]
 ----
 Try
-    message = RetrieveMessage()
+    Dim message = RetrieveMessage()
     Trace.Write($"Message received: {message}") ' Noncompliant
 Catch ex As Exception
     Trace.WriteLine(ex) ' Noncompliant
@@ -13,7 +13,7 @@ End Try
 [source,vbnet,diff-id=1,diff-type=compliant]
 ----
 Try
-    message = RetrieveMessage()
+    Dim message = RetrieveMessage()
     Trace.TraceInformation($"Message received: {message}")
 Catch ex As Exception
     Trace.TraceError(ex)