node: bump to 8.15.1

Several security fixes:
Node.js: Slowloris HTTP Denial of Service with keep-alive (CVE-2019-5737)
OpenSSL: 0-byte record padding oracle (CVE-2019-1559)

Signed-off-by: Hirokazu MORIKAWA <morikw2@gmail.com>

lang/node/Makefile

@@ -8,11 +8,11 @@
 include $(TOPDIR)/rules.mk
 
 PKG_NAME:=node
-PKG_VERSION:=v8.14.1
+PKG_VERSION:=v8.15.1
 PKG_RELEASE:=1
 PKG_SOURCE:=node-$(PKG_VERSION).tar.xz
 PKG_SOURCE_URL:=https://nodejs.org/dist/${PKG_VERSION}
-PKG_HASH:=b1df87803ddffb76fc6739f025f69f6b8288514fcd2f278f0d675ac3d52a6b9b
+PKG_HASH:=6b6486a3f452624941f6e11dd5f878c298d43e9c21b5f43ca1721dc7ce25add1
 
 HOST_BUILD_DEPENDS:=python/host
 PKG_BUILD_DEPENDS:=python/host