Make networks vms relations distinct

Make networks vms relations distinct, otherwise the Vm count
could be shown as higher, if the the vm has multiple ports
plugged into the same network.

Fixes BZ:
https://bugzilla.redhat.com/show_bug.cgi?id=1479667

app/models/cloud_network.rb

@@ -12,9 +12,9 @@ class CloudNetwork < ApplicationRecord
   has_many :cloud_subnets, :dependent => :destroy
   has_many :network_routers, -> { distinct }, :through => :cloud_subnets
   has_many :public_networks, -> { distinct }, :through => :cloud_subnets
-  has_many :network_ports, :through => :cloud_subnets
+  has_many :network_ports, -> { distinct }, :through => :cloud_subnets
   has_many :floating_ips,  :dependent => :destroy
-  has_many :vms, :through => :network_ports, :source => :device, :source_type => 'VmOrTemplate'
+  has_many :vms, -> { distinct }, :through => :network_ports, :source => :device, :source_type => 'VmOrTemplate'
 
   has_many :public_network_vms, -> { distinct }, :through => :public_network_routers, :source => :vms
   has_many :public_network_routers, :foreign_key => :cloud_network_id, :class_name => NetworkRouter
@@ -42,7 +42,7 @@ class CloudNetwork < ApplicationRecord
     end
   end
 
-  virtual_total :total_vms, :vms, :uses => :vms
+  virtual_total :total_vms, :vms
 
   def self.class_by_ems(ext_management_system, _external = false)
     # TODO: A factory on ExtManagementSystem to return class for each provider