node: fix CXXFLAGS on host install

Now really fixes the build on Debian Jessie...

patches/packages/openwrt/0005-node-update-to-v0.12.14.patch

@@ -7,7 +7,7 @@ While we're at it, also enable parallel builds.
 Signed-off-by: Matthias Schiffer <mschiffer@universe-factory.net>
 
 diff --git a/lang/node/Makefile b/lang/node/Makefile
-index 243c8a5..bde7906 100644
+index 243c8a5..ed35e17 100644
 --- a/lang/node/Makefile
 +++ b/lang/node/Makefile
 @@ -8,17 +8,21 @@
@@ -34,11 +34,15 @@ index 243c8a5..bde7906 100644
  PKG_MAINTAINER:=John Crispin <blogic@openwrt.org>
  PKG_LICENSE:=
  
-@@ -56,6 +60,8 @@ HOST_CONFIGURE_ARGS:= \
+@@ -56,6 +60,12 @@ HOST_CONFIGURE_ARGS:= \
  
  HOST_CONFIGURE_CMD:=python ./configure
  
 +HOST_MAKE_FLAGS += CXXFLAGS='-std=c++11'
++
++define Host/Install
++	$(MAKE) -C $(HOST_BUILD_DIR) $(HOST_MAKE_FLAGS) install
++endef
 +
  define Build/InstallDev
  	$(INSTALL_DIR) $(1)/usr/include