MINOR: mailers: make it possible to configure the connection timeout

This patch introduces a configurable connection timeout for mailers
with a new "timeout mail <time>" directive.

Acked-by: Simon Horman <horms@verge.net.au>
diff --git a/include/types/mailers.h b/include/types/mailers.h
index 07374a7..2b88442 100644
--- a/include/types/mailers.h
+++ b/include/types/mailers.h
@@ -56,6 +56,9 @@
 	struct mailers *next;	        /* next mailers section */
 	int count;			/* total number of mailers in this mailers section */
 	int users;			/* number of users of this mailers section */
+	struct {			/* time to: */
+		int mail;		/*   try connecting to mailserver and sending a email */
+	} timeout;
 };