Fix note on TcpClient constructor about IPv4 (dotnet#8462)

Author: rzikm

xml/System.Net.Sockets/TcpClient.xml

@@ -131,7 +131,7 @@
  This constructor creates a new <xref:System.Net.Sockets.TcpClient> and allows the underlying service provider to assign the most appropriate local IP address and port number. You must first call the <xref:System.Net.Sockets.TcpClient.Connect%2A> method before sending and receiving data.  
 
 > [!NOTE]
->  This constructor works only with IPv4 address types.  
+>  On .NET Framework, this constructor works only with IPv4 address types.  
 
 > [!NOTE]
 >  This member outputs trace information when you enable network tracing in your application. For more information, see [Network Tracing in the .NET Framework](/dotnet/framework/network-programming/network-tracing).