strongswan: swanctl: make send_cert local

When support for send_cert was added in 4b9453b9a4, the $send_cert
variable was inadvertently global.  Make it local to avoid polluting the
global namespace and make the code easier to reason about.

Fixes: 4b9453b9a4 ("strongswan: Add support for send_cert option")
Signed-off-by: Kevin Locke <kevin@kevinlocke.name>

net/strongswan/files/swanctl.init

@@ -459,6 +459,7 @@ config_remote() {
 	local local_key
 	local ca_cert
 	local rekeytime
+	local send_cert
 	local remote_ca_certs
 	local pools
 	local eap_id