LESS Customizer doesn't play well with newer PHP

[benlk]

As reported in HS#4080,

https://github.com/INN/largo/blob/c41d8519370b48a6e53ce36b3b516d3e54e39d66/inc/custom-less-variables.php#L773

Warning: preg_match_all(): Compilation failed: invalid range in character class at offset 44 in /wp-content/themes/largo/inc/custom-less-variables.php on line 776

Warning: Invalid argument supplied for foreach() in /wp-content/themes/largo/inc/custom-less-variables.php on line 778

This can be fixed with, as @joshdarby noted in that thread.

-               $pattern = '#/\*\*\s+(?<comment>.*)\s+\*/\s*@(?P<name>[\w-_]+):\s*(?P<value>[^;]*);#Us';
+               $pattern = '#/\*\*\s+(?<comment>.*)\s+\*/\s*@(?P<name>[\w\-_]+):\s*(?P<value>[^;]*);#Us';