readme: Remove mentions of Gmail's "less secure app access"

README.md

@@ -1150,18 +1150,13 @@ In order to enable IMAP access go to the Gmail web interface - typically
 
 ### Password Authentication
 Gmail prevents password authentication by default. To enable
-password-authenticated IMAP access, one must either set up an "app password"
-or enable "less secure app access".
+password-authenticated IMAP access, one must set up an "app password".
 
 To set up an "app password", navigate to
 [https://myaccount.google.com/apppasswords](https://myaccount.google.com/apppasswords)
 and select app "Mail" and an appropriate device, e.g. "Mac", then click
 Generate.
 
-To enable "less secure app access", go to
-[myaccount.google.com/security](https://myaccount.google.com/security) and
-under `Less secure app access` click `Turn on access (not recommended)`.
-
 ### OAuth 2.0 Authentication
 Google OAuth 2.0 application review has not yet been requested for nmail, and
 as such users need to request an invitation to use this. Please send an email