package: add libesmtp

This is a library for sending email through SMTP.

Signed-off-by: Sagaert Johan <sagaert.johan@skynet.be>
Signed-off-by: Peter Korsgaard <jacmet@sunsite.dk>
diff --git a/package/Config.in b/package/Config.in
index adebd4b..b6df18a 100644
--- a/package/Config.in
+++ b/package/Config.in
@@ -336,6 +336,7 @@
 source "package/libcgicc/Config.in"
 source "package/libcurl/Config.in"
 source "package/libdnet/Config.in"
+source "package/libesmtp/Config.in"
 source "package/libeXosip2/Config.in"
 source "package/libidn/Config.in"
 source "package/libmicrohttpd/Config.in"