Fix B#4928 import vcenter networks with same name in different clusters

src/vmm_mad/remotes/vcenter/vcenter_driver.rb

@@ -517,9 +517,10 @@ class VIClient
                 next if !n[:host][0]
 
                # Networks can be in several cluster, create one per cluster
+                net_names = []
                 Array(n[:host]).each{ |host_system|
                     net_name = "#{n.name} - #{host_system.parent.name}"
-
+                    if !net_names.include?(net_name)
                         if !vnpool["VNET[BRIDGE=\"#{n[:name]}\"]/\
                                 TEMPLATE[VCENTER_TYPE=\"Port Group\"]"]
                             one_nets << {
@@ -532,6 +533,8 @@ class VIClient
                                             "VN_MAD = \"dummy\"\n" \
                                             "VCENTER_TYPE = \"Port Group\""
                             }
+                            net_names << net_name
+                        end
                     end
                 }
             }