Replaced .txt rfc links to html

Signed-off-by: mrgarris0n <gergely.karacsonyi@gmail.com>

Author: mrgarris0n

_data/external_links.yml

@@ -432,12 +432,12 @@ welf:
 
 rfc-822:
   id: rfc-822
-  url: https://www.ietf.org/rfc/rfc822.txt
+  url: https://tools.ietf.org/html/rfc822
   title: [ "RFC-822" ]
 
 rfc-3162:
   id: rfc-3162
-  url: https://www.ietf.org/rfc/rfc3162.txt
+  url: https://tools.ietf.org/html/rfc3162
   title: [ "RFC-3162" ]
 
 rfc-3164:
@@ -447,17 +447,17 @@ rfc-3164:
 
 rfc-3339:
   id: rfc-3339
-  url: https://www.ietf.org/rfc/rfc3339.txt
+  url: https://tools.ietf.org/html/rfc3339
   title: [ "RFC-3339" ]
 
 rfc-3526:
   id: rfc-3526
-  url: https://www.ietf.org/rfc/rfc3526.txt
+  url: https://tools.ietf.org/html/rfc3526
   title: [ "RFC-3526" ]
 
 rfc-4122:
   id: rfc-4122
-  url: https://www.ietf.org/rfc/rfc4122.txt
+  url: https://tools.ietf.org/html/rfc4122
   title: [ "RFC-4122" ]
 
 rfc-4180: