Issue 48: ExtensionWhitelist should use the default manifest

[jumde]

fix #48

Description

Local-Data extension was failing the build with this error:

13:57:34 
13:57:35 Unhandled rejection: { Error: ENOENT: no such file or directory, open 'manifests/local-data-files-updater/ExtensionWhitelist-manifest.json'
13:57:35     at Object.openSync (fs.js:450:3)
13:57:35     at Object.readFileSync (fs.js:350:35)
13:57:35     at Object.parseManifest (/Users/jenkins/jenkins/workspace/brave-core-ext-local-data-files-update-publish-dev/lib/util.js:77:19)
13:57:35     at processDATFile (/Users/jenkins/jenkins/workspace/brave-core-ext-local-data-files-update-publish-dev/scripts/packageComponent.js:121:31)
13:57:35     at Array.forEach (<anonymous>)
13:57:35     at util.createTableIfNotExists.then (/Users/jenkins/jenkins/workspace/brave-core-ext-local-data-files-update-publish-dev/scripts/packageComponent.js:163:6)

The ExtensionWhitelist should use the default manifest and not ExtensionWhitelist-manifest

[jumde]

Build passed: https://staging.ci.brave.com/view/all-extensions/job/brave-core-ext-local-data-files-update-publish-dev/25/

[emerick]

LGTM