use NULL to load plugins from default plugin directory

src/charon/plugins/sql/Makefile.am

@@ -3,7 +3,6 @@ INCLUDES = -I$(top_srcdir)/src/libstrongswan -I$(top_srcdir)/src/charon
 
 AM_CFLAGS = -rdynamic \
   -DSTRONGSWAN_CONF=\"${strongswan_conf}\" \
-  -DIPSEC_PLUGINDIR=\"${plugindir}\" \
   -DPLUGINS=\""${libstrongswan_plugins}\""
 
 plugin_LTLIBRARIES = libstrongswan-sql.la

src/charon/plugins/sql/pool.c

@@ -634,7 +634,7 @@ int main(int argc, char *argv[])
 		fprintf(stderr, "integrity check of pool failed\n");
 		exit(SS_RC_DAEMON_INTEGRITY);
 	}
-	if (!lib->plugins->load(lib->plugins, IPSEC_PLUGINDIR,
+	if (!lib->plugins->load(lib->plugins, NULL,
 			lib->settings->get_str(lib->settings, "pool.load", PLUGINS)))
 	{
 		exit(SS_RC_INITIALIZATION_FAILED);