Documentation: Supplement 'encrypt-then-MAC' supported by Apache MINA

'encrypt-then-MAC' hash algorithms were added to Apache MINA in context
of this request: [1]. See also the RFC-7366 for more details: [2].

[1] https://issues.apache.org/jira/browse/SSHD-946
[2] https://datatracker.ietf.org/doc/html/rfc7366

Release-Notes: Supplement 'encrypt-then-MAC' supported by Apache MINA
Change-Id: If052dc0e2e7001c056db29ba14ff8b10abd71a7e

Documentation/config-gerrit.txt

diff --git a/Documentation/config-gerrit.txt b/Documentation/config-gerrit.txt
index a98b54a..3b650e8 100644
--- a/Documentation/config-gerrit.txt
+++ b/Documentation/config-gerrit.txt
@@ -5104,6 +5104,9 @@
 * `hmac-sha1-96`
 * `hmac-sha2-256`
 * `hmac-sha2-512`
+* `hmac-sha1-etm@openssh.com`
+* `hmac-sha2-256-etm@openssh.com`
+* `hmac-sha2-512-etm@openssh.com`
 +
 By default, all supported MACs are available.