Update RFC 2617 hyperlink in selecting-a-credential-type.md (#1) (dotnet#35121)

Author: thebarrettlo

docs/framework/wcf/feature-details/selecting-a-credential-type.md

@@ -23,8 +23,8 @@ ms.assetid: bf707063-3f30-4304-ab53-0e63413728a8
 |Setting|Description|  
 |-------------|-----------------|  
 |None|Specifies that the client does not need to present any credential. This translates to an anonymous client.|  
-|Basic|Specifies basic authentication for the client. For additional information, see RFC2617—[HTTP Authentication: Basic and Digest Authentication](ftp://ftp.rfc-editor.org/in-notes/rfc2617.txt).|  
-|Digest|Specifies digest authentication for the client. For additional information, see RFC2617—[HTTP Authentication: Basic and Digest Authentication](ftp://ftp.rfc-editor.org/in-notes/rfc2617.txt).|  
+|Basic|Specifies basic authentication for the client. For additional information, see RFC2617—[HTTP Authentication: Basic and Digest Authentication](https://www.rfc-editor.org/rfc/rfc2617).|  
+|Digest|Specifies digest authentication for the client. For additional information, see RFC2617—[HTTP Authentication: Basic and Digest Authentication](https://www.rfc-editor.org/rfc/rfc2617).|  
 |Ntlm|Specifies NT LAN Manager (NTLM) authentication. This is used when you cannot use Kerberos authentication for some reason. You can also disable its use as a fallback by setting the <xref:System.ServiceModel.Security.WindowsClientCredential.AllowNtlm%2A> property to `false`, which causes WCF to make a best-effort to throw an exception if NTLM is used. Note that setting this property to `false` may not prevent NTLM credentials from being sent over the wire.|  
 |Windows|Specifies Windows authentication. To specify only the Kerberos protocol on a Windows domain, set the <xref:System.ServiceModel.Security.WindowsClientCredential.AllowNtlm%2A> property to `false` (the default is `true`).|  
 |Certificate|Performs client authentication using an X.509 certificate.|