Remove paragraph on GPG/PGP keyservers.

Converted from getsops/sops@d5c5cd8

Signed-off-by: Felix Fontein <felix@fontein.de>

Author: felixfontein

content/en/docs/_index.md

@@ -876,14 +876,6 @@ Example: place the following in your `~/.bashrc`
 SOPS_GPG_EXEC = 'your_gpg_client_wrapper'
 ```
 
-## Specify a different GPG key server
-
-By default, SOPS uses the key server `keys.openpgp.org` to retrieve the
-GPG keys that are not present in the local keyring. This is no longer
-configurable. You can learn more about why from this write-up: [SKS
-Keyserver Network Under
-Attack](https://gist.github.com/rjhansen/67ab921ffb4084c865b3618d6955275f).
-
 ## Key groups
 
 By default, SOPS encrypts the data key for a file with each of the