fix build: put back ANDROID_SYS_HEADERS

compile-libvlc.sh

@@ -475,12 +475,14 @@ echo $VLC_BUILD_DIR
 LIBVLC_LIBS="libvlcjni"
 VLC_MODULES=`echo $VLC_MODULES|sed "s|vlc/$VLC_BUILD_DIR|../vlc/$VLC_BUILD_DIR|g"`
 VLC_SRC_DIR="../vlc"
+ANDROID_SYS_HEADERS="../android-headers"
 VLC_CONTRIB="$VLC_SRC_DIR/contrib/$TARGET_TUPLE"
 
 echo "Building NDK"
 
 $ANDROID_NDK/ndk-build -C libvlc \
     VLC_SRC_DIR="$VLC_SRC_DIR" \
+    ANDROID_SYS_HEADERS="$ANDROID_SYS_HEADERS" \
     VLC_BUILD_DIR="$VLC_SRC_DIR/$VLC_BUILD_DIR" \
     VLC_CONTRIB="$VLC_CONTRIB" \
     VLC_MODULES="$VLC_MODULES" \