Set php-fpm log_level default to fix 'unknown value'

[dalepgrant]

Before

$ sudo php-fpm8.2 -tt
[sudo] password for admin: 
[15-Oct-2025 04:47:24] NOTICE: [global]
... other bits
[15-Oct-2025 04:47:24] NOTICE:  log_level = unknown value
... etc etc

After

$ sudo php-fpm8.2 -tt
[15-Oct-2025 04:50:46] NOTICE: [global]
... other bits
[15-Oct-2025 04:50:46] NOTICE:  log_level = NOTICE
... etc etc