Switch to side-by-side view

--- a/tests/mail/mail.txt
+++ b/tests/mail/mail.txt
@@ -11,3 +11,5 @@
 message/rfc822	[file:///home/dockes/projets/fulltext/testrecoll/mail/thunderbird/Sent]	[Pronote: salut les genies.]	568	bytes	
 1 results
 message/rfc822	[file:///home/dockes/projets/fulltext/testrecoll/mail/thunderbird/Sent]	[De mieux en mieux]	557	bytes	
+1 results
+message/rfc822	[file:///home/dockes/projets/fulltext/testrecoll/mail/outmail]	[Message avec attachement textplain utf8]	1733	bytes