git-imap-send.txt: do verify SSL certificate for gmail.com

As a public service, it is unlikely that the Gmail server is configured
to throw a certificate that does not verify at the user.

Remove the `sslVerify=false` config from the Gmail example.

Also, comment it in the `example.com` example, and add a note to the
user explaining that they might want to uncomment it if they are having
trouble connecting. While at it, use an Asciidoc 'Note' section in the
Gmail example also.

Based-on-patch-by: Barbu Paul - Gheorghe <barbu.paul.gheorghe@gmail.com>
Helped-by: Junio C Hamano <gitster@pobox.com>
Signed-off-by: Philippe Blain <levraiphilippeblain@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

Documentation/git-imap-send.txt

@@ -85,10 +85,17 @@ Using direct mode with SSL:
     user = bob
     pass = p4ssw0rd
     port = 123
-    sslverify = false
+    ; sslVerify = false
 .........................
 
 
+[NOTE]
+You may want to use `sslVerify=false`
+while troubleshooting, if you suspect that the reason you are
+having trouble connecting is because the certificate you use at
+the private server `example.com` you are trying to set up (or
+have set up) may not be verified correctly.
+
 Using Gmail's IMAP interface:
 
 ---------
@@ -97,9 +104,9 @@ Using Gmail's IMAP interface:
 	host = imaps://imap.gmail.com
 	user = user@gmail.com
 	port = 993
-	sslverify = false
 ---------
 
+[NOTE]
 You might need to instead use: `folder = "[Google Mail]/Drafts"` if you get an error
 that the "Folder doesn't exist".