Upgrade third-party njs module to 950db73 aka 0.2.3.
Bump PORTREVISION.

<ChangeLog>

nginx modules:

*) Bugfix: making a subrequest from a Reply object caused

a segmentation fault.

*) Bugfix: getting the parent property of the main Request

object caused a segmentation fault.

Core:

*) Feature: added the pretty string representation for values.

*) Feature: correctly printing floating point numbers.

*) Feature: correctly parsing floating point numbers.

*) Feature: String.bytesFrom() method (decoding hex, base64,

base64url into a byte string).

*) Feature: String.padStart() and String.padEnd() methods.

*) Feature: added support of binary literals.

*) Improvement: added information about illegal token in number parsing.

*) Improvement: allowed uppercased O in octal literal values.

*) Improvement: added support for multiple arguments in console.log().

*) Bugfix: fixed applying call() to methods of external values.

*) Bugfix: fixed addition operator applied to an object.

*) Bugfix: fixed exception handling in njs_vm_value_to_ext_string().

*) Bugfix: fixed Number() with boolean, null and undefined arguments.

*) Bugfix: fixed error handling of setting non-numeric Array.length.

*) Bugfix: fixed autocompletion for global objects.

*) Bugfix: miscellaneous additional bugs have been fixed.

</ChangeLog>