Fix broken Markdown links [ci-skip]

Follow-up to rails#50879.

Author: jonathanhefner

actionpack/lib/action_controller/metal/conditional_get.rb

@@ -76,8 +76,7 @@ def etag(&etagger)
     # `:cache_control`
     # :   When given, will overwrite an existing `Cache-Control` header. For a list
     #     of `Cache-Control` directives, see the [article on
-    #     MDN](https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/Cache-Contr
-    #     ol).
+    #     MDN](https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/Cache-Control).
     #
     # `:template`
     # :   By default, the template digest for the current controller/action is

actionpack/lib/action_dispatch/middleware/remote_ip.rb

@@ -18,8 +18,8 @@ module ActionDispatch
   # 2616](https://www.w3.org/Protocols/rfc2616/rfc2616-sec4.html#sec4.2) requires.
   # Some Rack servers simply drop preceding headers, and only report the value
   # that was [given in the last
-  # header](https://andre.arko.net/2011/12/26/repeated-headers-and-ruby-web-server
-  # s). If you are behind multiple proxy servers (like NGINX to HAProxy to
+  # header](https://andre.arko.net/2011/12/26/repeated-headers-and-ruby-web-servers).
+  # If you are behind multiple proxy servers (like NGINX to HAProxy to
   # Unicorn) then you should test your Rack server to make sure your data is good.
   #
   # IF YOU DON'T USE A PROXY, THIS MAKES YOU VULNERABLE TO IP SPOOFING. This
@@ -117,10 +117,9 @@ def initialize(req, check_ip, proxies)
       # instead, so we check that too.
       #
       # As discussed in [this post about Rails IP
-      # Spoofing](https://web.archive.org/web/20170626095448/https://blog.gingerlime.c
-      # om/2012/rails-ip-spoofing-vulnerabilities-and-protection/), while the first IP
-      # in the list is likely to be the "originating" IP, it could also have been set
-      # by the client maliciously.
+      # Spoofing](https://web.archive.org/web/20170626095448/https://blog.gingerlime.com/2012/rails-ip-spoofing-vulnerabilities-and-protection/),
+      # while the first IP in the list is likely to be the "originating" IP, it
+      # could also have been set by the client maliciously.
       #
       # In order to find the first address that is (probably) accurate, we take the
       # list of IPs, remove known and trusted proxies, and then take the last address