configure: reword help for --without-npm

PR-URL: https://github.com/nodejs/node/pull/7471
Reviewed-By: Robert Jefe Lindstaedt <robert.lindstaedt@gmail.com>
Reviewed-By: James M Snell <jasnell@gmail.com>

configure

@@ -342,7 +342,7 @@ parser.add_option('--without-etw',
 parser.add_option('--without-npm',
     action='store_true',
     dest='without_npm',
-    help='don\'t install the bundled npm package manager')
+    help='do not install the bundled npm (package manager)')
 
 parser.add_option('--without-perfctr',
     action='store_true',