Log Message:
nginx: Update njs module to 0.5.0.

Changelog:
* nginx modules:

    *) Feature: introduced global "ngx" object.
       The following methods were added:
         ngx.log(level, msg)

       The following properties were added:
         ngx.INFO,
         ngx.WARN,
         ngx.ERR.

    *) Feature: added support for Buffer object where string
       is expected.

    *) Feature: added Buffer version of existing properties.
       The following properties were added:
       r.requestBuffer (r.requestBody),
       r.responseBuffer (r.responseBody),
       r.rawVariables (r.variables),
       s.rawVariables (s.variables).

       The following events were added in stream module:
       upstream (upload),
       downstream (download).

    *) Improvement: added aliases to existing properties.
       The following properties were added:
       r.requestText (r.requestBody),
       r.responseText (r.responseBody).

    *) Improvement: throwing an exception in r.internalRedirect()
       for a subrequest.

    *) Bugfix: fixed promise r.subrequest() with error_page redirect.

    *) Bugfix: fixed promise events handling.

* Core:

    *) Feature: added TypeScript definitions for built-in
       modules.
       Thanks to Jakub Jirutka.

    *) Feature: tracking unhandled promise rejection.

    *) Feature: added initial iterator support.
       Thanks to Artem S. Povalyukhin.

    *) Improvement: TypeScript definitions are refactored.
       Thanks to Jakub Jirutka.

    *) Improvement: added forgotten support for
       Object.prototype.valueOf() in Buffer.from().

    *) Bugfix: fixed heap-use-after-free in JSON.parse().

    *) Bugfix: fixed heap-use-after-free in JSON.stringify().

    *) Bugfix: fixed JSON.stringify() for arrays resizable via
       getters.

    *) Bugfix: fixed heap-buffer-overflow for
       RegExp.prototype[Symbol.replace].

    *) Bugfix: fixed returned value for Buffer.prototype.write*
       functions.

    *) Bugfix: fixed querystring.stringify().
       Thanks to Artem S. Povalyukhin.

    *) Bugfix: fixed the catch handler for
       Promise.prototype.finally().

    *) Bugfix: fixed querystring.parse().