Increase router instances in London to 30
Increase router instances in London to 30

We are expecting and increase in load and prefer to over-provision in
the first instance.

alphagov/paas-cf,alphagov/paas-cf,alphagov/paas-cf,alphagov/paas-cf,alphagov/paas-cf,alphagov/paas-cf,alphagov/paas-cf,alphagov/paas-cf