*/*: update NGINX JavaScript module 0.7.5 -> 0.7.6

<ChangeLog>

nginx modules:

*) Feature: improved r.args object. Added support for multiple

arguments with the same key. Added case sensitivity for
keys. Keys and values are percent-decoded now.

*) Bugfix: fixed r.headersOut setter for special headers.

Core:

*) Feature: added Symbol.for() and Symbol.keyfor().

*) Feature: added btoa() and atob() from WHATWG spec.

*) Bugfix: fixed large non-decimal literals.

*) Bugfix: fixed unicode argument trimming in parseInt().

*) Bugfix: fixed break instruction in a try-catch block.

*) Bugfix: fixed async function declaration in CLI.

</ChangeLog>