doc: send-email: fix broken list continuation

The list continuation has to be “immediately adjacent to the block
being attached”.[1]

[1]: https://web.archive.org/web/20251208172615/https://docs.asciidoctor.org/asciidoc/latest/lists/continuation/

Signed-off-by: Kristoffer Haugsbakk <[email protected]>
Signed-off-by: Junio C Hamano <[email protected]>

Author: LemmingAvalanche

Documentation/git-send-email.adoc

@@ -321,7 +321,6 @@ for instructions.
 	If disabled with `--no-use-imap-only`, the emails will be sent like usual.
 	Disabled by default, but the `sendemail.useImapOnly` configuration
 	variable can be used to enable it.
-
 +
 This feature requires setting up `git imap-send`. See linkgit:git-imap-send[1]
 for instructions.