Improve performance of Hardware#ipaddresses

Doesn't work with loaded networks though... might not want to merge
this.

app/models/hardware.rb

@@ -31,7 +31,7 @@ class Hardware < ApplicationRecord
   virtual_aggregate :allocated_disk_storage, :disks, :sum, :size
 
   def ipaddresses
-    @ipaddresses ||= networks.collect(&:ipaddress).compact.uniq + networks.collect(&:ipv6address).compact.uniq
+    @ipaddresses ||= networks.pluck(:ipaddress, :ipv6address).flatten.tap(&:compact!).uniq!
   end
 
   def hostnames