package/openswan: select libxcrypt if needed

Fix the following build failure raised since bump of glibc to version
2.39 in commit b5680f53d60acf8ff6010082f873438a39bd5d97:

/home/autobuild/autobuild/instance-7/output-1/build/openswan-3.0.0/programs/pluto/xauth.c:36:10: fatal error: crypt.h: No such file or directory
   36 | #include <crypt.h>
      |          ^~~~~~~~~

Fixes: b5680f53d60acf8ff6010082f873438a39bd5d97
 - http://autobuild.buildroot.org/results/df7cce809e3e4aa92e700a3fc5105c6c20f21f6b

Signed-off-by: Fabrice Fontaine <fontaine.fabrice@gmail.com>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>

package/openswan/Config.in

@@ -4,6 +4,7 @@ config BR2_PACKAGE_OPENSWAN
 	depends on BR2_TOOLCHAIN_HEADERS_AT_LEAST_3_4 # iproute2
 	select BR2_PACKAGE_GMP
 	select BR2_PACKAGE_IPROUTE2
+	select BR2_PACKAGE_LIBXCRYPT if BR2_TOOLCHAIN_USES_GLIBC
 	help
 	  Openswan is an implementation of IPsec for Linux
 

package/openswan/openswan.mk

@@ -22,6 +22,10 @@ OPENSWAN_DEPENDENCIES += libcurl
 OPENSWAN_MAKE_OPTS += USE_LIBCURL=true
 endif
 
+ifeq ($(BR2_PACKAGE_LIBXCRYPT),y)
+OPENSWAN_DEPENDENCIES += libxcrypt
+endif
+
 ifeq ($(BR2_PACKAGE_OPENSSL),y)
 OPENSWAN_DEPENDENCIES += openssl
 OPENSWAN_MAKE_OPTS += HAVE_OPENSSL=true