Update wp7_parser.js

Fails to add windows package, files with 0 size are not directories.
    [phonegap] adding the Windows Phone 8 platform...
    Fatal error:
    npm\node_modules\phonegap\node_modules\cordova\src\metadata\wp8_parser.
    js:220
                if(stat.size == 0 {
                                  ^
    SyntaxError: Unexpected token {
        at Module._compile (module.js:439:25)
        at Object.Module._extensions..js (module.js:474:10)
        at Module.load (module.js:356:32)
        at Function.Module._load (module.js:312:12)
        at Module.require (module.js:364:17)
        at Object.defineProperty.get [as parser] (c:\Users\AppData\Roaming\npm\node_modules\phonegap
    \node_modules\cordova\src\util.js:140:55)
        at Function.module.exports.supports (c:\Users\AppData\Roaming\npm\node_modules\phonegap\node
    _modules\cordova\src\platform.js:259:41)
        at call_into_create (c:\Users\AppData\Roaming\npm\node_modules\phonegap\node_modules\cordova
    \src\platform.js:295:24)
        at c:\Users\AppData\Roaming\npm\node_modules\phonegap\node_modules\cordova\src\platform.js:9
    6:29
        at c:\Users\AppData\Roaming\npm\node_modules\phonegap\node_modules\cordova\src\lazy_load.js:
    48:31