[exim] How to set option using output from system command?

[krzf83--- via Exim-users]

How to set option using output from system command?

deliver_queue_load_max = ${run{/bin/grep 'processor' /proc/cpuinfo -c}}

  fixed-point number expected for deliver_queue_load_max


deliver_queue_load_max = ${run{/bin/grep 'processor' /proc/cpuinfo -c}}{$value}

  fixed-point number expected for deliver_queue_load_max


deliver_queue_load_max = ${run{/bin/grep 'processor' /proc/cpuinfo -c}{$value}}

  fixed-point number expected for deliver_queue_load_max

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