build: use 0o octal notation in configure

This un-‘breaks’ the error message we print when using
Python 3 to run `configure`.

Refs: nodejs/help#1457

PR-URL: #22536
Reviewed-By: Gus Caplan <me@gus.host>
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>
Reviewed-By: Refael Ackermann <refack@gmail.com>
Reviewed-By: Richard Lau <riclau@uk.ibm.com>
Reviewed-By: Joyee Cheung <joyeec9h3@gmail.com>
Reviewed-By: Ruben Bridgewater <ruben@bridgewater.de>
Reviewed-By: Sakthipriyan Vairamani <thechargingvolcano@gmail.com>
Reviewed-By: James M Snell <jasnell@gmail.com>

configure

@@ -1575,7 +1575,7 @@ write('config.gypi', do_not_edit +
 
 write('config.status', '#!/bin/sh\nset -x\nexec ./configure ' +
       ' '.join([pipes.quote(arg) for arg in original_argv]) + '\n')
-os.chmod('config.status', 0775)
+os.chmod('config.status', 0o775)
 
 config = {
   'BUILDTYPE': 'Debug' if options.debug else 'Release',