www/nginx: Update 3rd party Module NJS

Update the NJS Modile to 0.7.6:
Notable new features:

• improved r.args: Now, duplicate keys are returned as an array, keys are case-sensitive, both keys and values are percent-decoded.
  
  For example, the query string
  
  'a=1&b=%32&A=3&b=4&B=two%20words'
  
  is converted to r.args as:
  
  {a: "1", b: ["2", "4"], A: "3", B: "two words"}
  
  Changes with njs 0.7.6 19 Jul 2022
  
  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.

Sponsored by: Netzkommune GmbH