runtime(doc): update and remove  some invalid links

closes: #14748

Co-authored-by: zeertzjq <zeertzjq@outlook.com>
Signed-off-by: Christian Brabandt <cb@256bit.org>
diff --git a/runtime/doc/pi_netrw.txt b/runtime/doc/pi_netrw.txt
index 3efc60f..aeaca0b 100644
--- a/runtime/doc/pi_netrw.txt
+++ b/runtime/doc/pi_netrw.txt
@@ -1,4 +1,4 @@
-*pi_netrw.txt*  For Vim version 9.1.  Last change: 2024 May 08
+*pi_netrw.txt*  For Vim version 9.1.  Last change: 2024 May 11
 
 	    ------------------------------------------------
 	    NETRW REFERENCE MANUAL    by Charles E. Campbell
@@ -2033,11 +2033,7 @@
     better way to do that: I can use a regular ssh account which uses a
     password to access the material without the need to key-in the password
     each time. It's good for security and convenience. I tried ssh public key
-    authorization + ssh-agent, implementing this, and it works! Here are two
-    links with instructions:
-
-    http://www.ibm.com/developerworks/library/l-keyc2/
-    http://sial.org/howto/openssh/publickey-auth/
+    authorization + ssh-agent, implementing this, and it works!
 
 
     Ssh hints: