Do not try to configure electron's node against vendored ICU headers

--- a/electron/script/generate-config-gypi.py
+++ b/electron/script/generate-config-gypi.py
@@ -14,6 +14,7 @@
 def run_node_configure(target_cpu):
   configure = os.path.join(NODE_DIR, 'configure.py')
   args = ['--dest-cpu', target_cpu]
+  args+= ['--with-intl=system-icu']
   # Enabled in Chromium's V8, will be disabled on 32bit via
   # common.gypi rules
   args += ['--experimental-enable-pointer-compression']