package/glog: don't override dependencies

Don't override GLOG_DEPENDENCIES in a conditional

Signed-off-by: Fabrice Fontaine <fontaine.fabrice@gmail.com>
Signed-off-by: Yann E. MORIN <yann.morin.1998@free.fr>
(cherry picked from commit 1f9e65b2f34f11d93709a090df799150e00b519e)
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>

package/glog/glog.mk

@@ -13,7 +13,7 @@ GLOG_CONF_OPTS = \
 	$(if $(BR2_TOOLCHAIN_HAS_THREADS),-DWITH_THREADS=ON, -DWITH_THREADS=OFF)
 
 ifeq ($(BR2_PACKAGE_GFLAGS),y)
-GLOG_DEPENDENCIES = gflags
+GLOG_DEPENDENCIES += gflags
 GLOG_CONF_OPTS += -DWITH_GFLAGS=ON
 else
 GLOG_CONF_OPTS += -DWITH_GFLAGS=OFF