PHPCompatibility 7.4 : Array and string offset access syntax with curly braces is deprecated in PHP 7.4. Use square brackets instead.

Problem/Motivation

A PHP-7.4 notice deprecation:-

FILE: ..\oauth\lib\OAuth.php

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FOUND 0 ERRORS AND 2 WARNINGS AFFECTING 1 LINE
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 114 | WARNING | [x] Curly brace syntax for accessing array elements and string offsets has been deprecated in PHP 7.4. Found:
     |         |     $built{$i}
 114 | WARNING | [x] Curly brace syntax for accessing array elements and string offsets has been deprecated in PHP 7.4. Found:
     |         |     $signature{$i}
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Steps to reproduce

Switch to php7.4, check logs

Proposed resolution

I would suggest to apply a patch