package/heirloom-mailx: fix attachments typo in help text

Signed-off-by: Peter Korsgaard <peter@korsgaard.com>
Signed-off-by: Yann E. MORIN <yann.morin.1998@free.fr>
(cherry picked from commit 30a9d7d129908080667845fdc167f149cb92c665)
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>

package/heirloom-mailx/Config.in

@@ -13,7 +13,7 @@ config BR2_PACKAGE_HEIRLOOM_MAILX
 	  importantly on embedded systems, as a mail composition
 	  program and SMTP client, in order to send e-mail from shell
 	  scripts. It supports SMTP authentication (login, plain,
-	  cram-md5), SMTPS, MIME encoding of attachements, and more.
+	  cram-md5), SMTPS, MIME encoding of attachments, and more.
 
 	  http://heirloom.sourceforge.net/mailx.html