Change offset of php-fpm-exporter port

Use offsets for the apache-exporter and the php-fpm-exporter that do
not overlap when multiple instances run on the same machine...
2 jobs for master in 2 minutes and 17 seconds (queued for 1 second)
Status Job ID Name Coverage
  Build
passed #7751
build

00:01:55

 
  Release
passed #7752
release

00:00:21