[PATCH v3] git-send-email.txt: mention less secure app access with Gmail

[Denton Liu <liu.denton@gmail.com>]

Google may have changed Gmail security and now less secure app access
needs to be explicitly enabled if two-factor authentication is not in
place, otherwise send-email fails with:

	5.7.8 Username and Password not accepted. Learn more at
	5.7.8  https://support.google.com/mail/?p=BadCredentials

Document steps required to make this work.

Original-patch-by: Vasyl Vavrychuk <vvavrychuk@gmail.com>
Signed-off-by: Denton Liu <liu.denton@gmail.com>
---
Range-diff against v2:
1:  2bcfd1403f < -:  ---------- Documentation/git-send-email.txt: Mention less secure app access might need to enable.
-:  ---------- > 1:  274475559a git-send-email.txt: mention less secure app access with Gmail

 Documentation/git-send-email.txt | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/Documentation/git-send-email.txt b/Documentation/git-send-email.txt
index 0a69810147..0db0783f2f 100644
--- a/Documentation/git-send-email.txt
+++ b/Documentation/git-send-email.txt
@@ -494,10 +494,14 @@ edit ~/.gitconfig to specify your account settings:
 	smtpServerPort = 587
 ----
 
-If you have multifactor authentication setup on your gmail account, you will
+If you have multi-factor authentication set up on your Gmail account, you will
 need to generate an app-specific password for use with 'git send-email'. Visit
 https://security.google.com/settings/security/apppasswords to create it.
 
+If you do not have multi-factor authentication set up on your Gmail account,
+you will need to allow less secure app access. Visit
+https://myaccount.google.com/lesssecureapps to enable it.
+
 Once your commits are ready to be sent to the mailing list, run the
 following commands:
 
-- 
2.30.0