2.7.3 prep (#9817)

* Update changelog for 2.7.2 release

* Release 2.7.2

* helpful: Add an edge case for arguments w/ contained spaces (#9813)

Fixes #9811

(cherry picked from commit 3ae9d7e03a)

* fixes #9805 (#9816)

(cherry picked from commit d1577280ad)

---------

Co-authored-by: Will Greenberg <willg@eff.org>

certbot/docs/cli-help.txt

@@ -36,7 +36,7 @@ manage your account:
   --agree-tos       Agree to the ACME server's Subscriber Agreement
    -m EMAIL         Email address for important account notifications
 
-optional arguments:
+options:
   -h, --help            show this help message and exit
   -c CONFIG_FILE, --config CONFIG_FILE
                         path to config file (default: /etc/letsencrypt/cli.ini
@@ -122,7 +122,7 @@ optional arguments:
                         case, and to know when to deprecate support for past
                         Python versions and flags. If you wish to hide this
                         information from the Let's Encrypt server, set this to
-                        "". (default: CertbotACMEClient/2.7.1 (certbot;
+                        "". (default: CertbotACMEClient/2.7.2 (certbot;
                         OS_NAME OS_VERSION) Authenticator/XXX Installer/YYY
                         (SUBCOMMAND; flags: FLAGS) Py/major.minor.patchlevel).
                         The flags encoded in the user agent are: --duplicate,