Use correct statsd port in Toolforge environment

Port 2003 is for talking to Graphite/Carbon directly.

It seems that the default statsd port 8125 is open on these hosts [1],
and that would be consistent with other tools like ORES which
appear to just use the default ports.

[1]

nc -vz -u cloudmetrics1002.eqiad.wmnet 8125
cloudmetrics1002.eqiad.wmnet [10.64.4.15] 8125 (?) open

Bug: T279236