package/socketcand: don't override dependencies

Don't override SOCKETCAND_DEPENDENCIES in a conditional

Signed-off-by: Fabrice Fontaine <fontaine.fabrice@gmail.com>
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>
(cherry picked from commit 2bb820cb9ef7d52dd97504761c13fc5e65fe556a)
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>

package/socketcand/socketcand.mk

@@ -11,7 +11,7 @@ SOCKETCAND_LICENSE = BSD-3-Clause or GPL-2.0
 SOCKETCAND_LICENSE_FILES = socketcand.c
 
 ifeq ($(BR2_PACKAGE_LIBCONFIG),y)
-SOCKETCAND_DEPENDENCIES = libconfig
+SOCKETCAND_DEPENDENCIES += libconfig
 else
 SOCKETCAND_CONF_OPTS = --without-config
 endif