dont stringify prefix for vip networks

Author: fmoehler

src/bosh-director/lib/bosh/director/deployment_plan/vip_network_subnet.rb

@@ -27,7 +27,7 @@ def self.parse(subnet_spec, network_name, azs)
       def initialize(static_ips, availability_zone_names, prefix)
         @static_ips = static_ips
         @availability_zone_names = availability_zone_names
-        @prefix = prefix.to_s
+        @prefix = prefix
       end
 
       def is_reservable?(ip)

src/bosh-director/spec/unit/bosh/director/deployment_plan/network_planner/reservation_reconciler_spec.rb

@@ -210,7 +210,7 @@ module Bosh::Director::DeploymentPlan
         end
 
         context 'when the existing ip is part of a vip static network but the desired network is a global vip network' do
-          let(:network) { VipNetwork.new('static-vip-network', nil, [], '32', per_spec_logger) }
+          let(:network) { VipNetwork.new('static-vip-network', nil, [], 32, per_spec_logger) }
           let(:network_spec) do
             {
               'name' => 'global-vip-network',