Set fix-process-count option for php-fpm-exporter

conf/services.d/php-fpm-exporter/run

 #!/bin/sh
 . /etc/apache2/envvars
 export HOME=/
-exec /usr/sbin/php-fpm-exporter server "--phpfpm.scrape-uri=unix:///run/php/php7.4-fpm.sock;/status" --web.listen-address=:$PHP_FPM_EXPORTER_PORT
+exec /usr/sbin/php-fpm-exporter server "--phpfpm.scrape-uri=unix:///run/php/php7.4-fpm.sock;/status" --web.listen-address=:$PHP_FPM_EXPORTER_PORT --phpfpm.fix-process-count