package/strongswan: drop BR2_PACKAGE_STRONGSWAN_SCEP

scepclient is unrecognized since bump to version 5.9.8 in commit
b79d735139282ecf052dc89d4c221bbd16447112 and
https://github.com/strongswan/strongswan/commit/8716f7c03c6193b1cb53837243177f36280ff4f7:

configure: WARNING: unrecognized options: --disable-gtk-doc, --disable-gtk-doc-html, --disable-doc, --disable-docs, --disable-documentation, --with-xmlto, --with-fop, --enable-ipv6, --disable-nls, --enable-scepclient

Fixes: b79d735139282ecf052dc89d4c221bbd16447112

Signed-off-by: Fabrice Fontaine <fontaine.fabrice@gmail.com>
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>
(cherry picked from commit ed2090717f657c1f19bb7bd62c97e17a7bf3ff50)
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>

Config.in.legacy

@@ -146,6 +146,16 @@ endif
 
 comment "Legacy options removed in 2023.02"
 
+config BR2_PACKAGE_STRONGSWAN_SCEP
+	bool "strongswan SCEP client tool removed"
+	select BR2_LEGACY
+	help
+	  "ipsec scepclient" tool has been removed and replaced by the
+	  pki subcommands "pki --scep" and "pki --scepca" which
+	  implement the new SCEP RFC 8894 standard that was released in
+	  September 2020 and which supports trusted "certificate
+	  renewal" based on the existing client certificate.
+
 config BR2_PACKAGE_PUGIXML_HEADER_ONLY
 	bool "pugixml header-only removed"
 	select BR2_LEGACY

package/strongswan/Config.in

@@ -204,9 +204,6 @@ config BR2_PACKAGE_STRONGSWAN_PKI
 	bool "Enable pki certificate utility"
 	default y
 
-config BR2_PACKAGE_STRONGSWAN_SCEP
-	bool "Enable SCEP client tool"
-
 config BR2_PACKAGE_STRONGSWAN_SCRIPTS
 	bool "Enable additional utilities (found in scripts directory)"
 	default y

package/strongswan/strongswan.mk

@@ -33,7 +33,6 @@ STRONGSWAN_CONF_OPTS += \
 	--enable-stroke=$(if $(BR2_PACKAGE_STRONGSWAN_STROKE),yes,no) \
 	--enable-sql=$(if $(BR2_PACKAGE_STRONGSWAN_SQL),yes,no) \
 	--enable-pki=$(if $(BR2_PACKAGE_STRONGSWAN_PKI),yes,no) \
-	--enable-scepclient=$(if $(BR2_PACKAGE_STRONGSWAN_SCEP),yes,no) \
 	--enable-scripts=$(if $(BR2_PACKAGE_STRONGSWAN_SCRIPTS),yes,no) \
 	--enable-vici=$(if $(BR2_PACKAGE_STRONGSWAN_VICI),yes,no) \
 	--enable-swanctl=$(if $(BR2_PACKAGE_STRONGSWAN_VICI),yes,no) \