Add a control to the web gui to allow the setting of leftsendcert in IPSec
In some IPSec tunnels the responder end requires the initiator to set send the certificate and that's only possible by setting leftsendcert=always or yes in ipsec.conf.
Currently we only set that if you are using IKEv2 with EAP. Some other cases require it to establish a tunnel.
This patch allowed that to connect: http://files.atx.pfsense.org/jimp/patches/rsasig-leftsendcert-always.diff