Reduce the max-servers in rax-ord from 195 to 100, and revert the
boot-timeout from the 300 we tried back down to 120 like the others.
We're continuing to see server create calls taking longer to report
active than nodepool is willing to wait, but also may be witnessing
the results of API rate limiting or systemic slowness. Reducing the
number of instances we attempt to boot there may give us a clearer
picture of whether that's the case.
Change-Id: Ife7035ba64b457d964c8497da0d9872e41769123