Changelog: sso -> Single Sign-On

CHANGES.md

@@ -9,7 +9,7 @@ This release also moves the location of the `synctl` script; see the [upgrade no
 Internal Changes
 ----------------
 
-- Tweak copy for default sso account details template to better adhere to mobile app store guidelines. ([\#12265](https://github.com/matrix-org/synapse/issues/12265), [\#12260](https://github.com/matrix-org/synapse/issues/12260))
+- Tweak copy for default Single Sign-On account details template to better adhere to mobile app store guidelines. ([\#12265](https://github.com/matrix-org/synapse/issues/12265), [\#12260](https://github.com/matrix-org/synapse/issues/12260))
 
 
 Synapse 1.55.0rc1 (2022-03-15)