Vcenter only:vcenter plugin is tring to delete the dv_port_group continuously

build R5.0.1 build 139

vcenter plugin is trying to delete the dvportgrop continuously.It is overflowing the recent tasks in vcenter.We should not try to delete the dv_port_group

bug
====
[2018-07-10 12:50:01,070] [INFO ] [Thread-3:VCenterDB@794] [Found <dpg c4k4u14_dvpg, dvs c4k4_dvs, datacenter c4_datacenter11, vCenter https://10.204.217.246/sdk>.]
[2018-07-10 12:50:06,075] [INFO ] [Thread-3:VCenterNotify@664] [+++++++++++++ Done syncing +++++++++++++++++++++]
[2018-07-10 12:50:06,075] [INFO ] [Thread-3:VCenterNotify@667] [+++++++++++++ Waiting for events +++++++++++++++++++++]
[2018-07-10 12:50:06,075] [INFO ] [Thread-3:VncDB@155] [ Checking if api-server is alive and kicking..]
[2018-07-10 12:50:06,075] [INFO ] [Thread-3:ApiConnectorImpl@217] [>> Request: GET, /projects]
[2018-07-10 12:50:06,078] [INFO ] [Thread-3:ApiConnectorImpl@239] [<< Response Status: HTTP/1.1 200 OK]
[2018-07-10 12:50:06,080] [INFO ] [Thread-3:VncDB@171] [ Api-server alive. Got the pulse..]
[2018-07-10 12:50:06,080] [INFO ] [Thread-3:VCenterNotify@642] [+++++++++++++ Start syncing +++++++++++++++++++++]
[2018-07-10 12:50:06,080] [INFO ] [Thread-3:VncDB@813] [Start reading virtual networks from the API server ...]
[2018-07-10 12:50:06,080] [INFO ] [Thread-3:ApiConnectorImpl@217] [>> Request: GET, /virtual-networks]
[2018-07-10 12:50:06,084] [INFO ] [Thread-3:ApiConnectorImpl@239] [<< Response Status: HTTP/1.1 200 OK]
[2018-07-10 12:50:06,086] [INFO ] [Thread-3:ApiConnectorImpl@217] [>> Request: GET, /virtual-network/2abc2b5c-8da9-4227-acc8-dd8f949891d2]
[2018-07-10 12:50:06,089] [INFO ] [Thread-3:ApiConnectorImpl@239] [<< Response Status: HTTP/1.1 200 OK]
[2018-07-10 12:50:06,091] [INFO ] [Thread-3:ApiConnectorImpl@217] [>> Request: GET, /virtual-network/007f8dd7-8bc5-42ef-8036-eac1374701c9]
[2018-07-10 12:50:06,094] [INFO ] [Thread-3:ApiConnectorImpl@239] [<< Response Status: HTTP/1.1 200 OK]
[2018-07-10 12:50:06,096] [INFO ] [Thread-3:ApiConnectorImpl@217] [>> Request: GET, /virtual-network/a9ba499e-dd29-4dd9-ac53-9a283b668526]
[2018-07-10 12:50:06,101] [INFO ] [Thread-3:ApiConnectorImpl@239] [<< Response Status: HTTP/1.1 200 OK]
[2018-07-10 12:50:06,103] [INFO ] [Thread-3:ApiConnectorImpl@217] [>> Request: GET, /virtual-network/33a11739-d562-4329-9abe-946d55c1d7b0]
[2018-07-10 12:50:06,107] [INFO ] [Thread-3:ApiConnectorImpl@239] [<< Response Status: HTTP/1.1 200 OK]
[2018-07-10 12:50:06,109] [INFO ] [Thread-3:ApiConnectorImpl@217] [>> Request: GET, /virtual-network/24da76ed-9534-47bb-b396-f4c8d2134af0]
[2018-07-10 12:50:06,112] [INFO ] [Thread-3:ApiConnectorImpl@239] [<< Response Status: HTTP/1.1 200 OK]
[2018-07-10 12:50:06,114] [INFO ] [Thread-3:VncDB@846] [Done reading from the API server, found 2 Virtual Networks]
[2018-07-10 12:50:06,114] [INFO ] [Thread-3:VCenterDB@885] [Start reading virtual networks from vcenter ...]
[2018-07-10 12:50:06,134] [ERROR] [Thread-3:VCenterDB@688] [dvSwitch: c4k4_dvs Datacenter: c4_datacenter11 Private VLAN NOTconfigured]
[2018-07-10 12:50:06,134] [ERROR] [Thread-3:VirtualNetworkInfo@277] [VN <ctest-vCenter-55191957, f90106d9-fc85-3c37-a483-bc78ae8fa5a6>Cannot populate vlan, private vlan not configured on dvSwitch: c4k4_dvs Datacenter: c4_datacenter11]
[2018-07-10 12:50:06,140] [INFO ] [Thread-3:VirtualNetworkInfo@401] [Set ipPoolId to null for VN <ctest-vCenter-55191957, f90106d9-fc85-3c37-a483-bc78ae8fa5a6>]
[2018-07-10 12:50:06,140] [INFO ] [Thread-3:VCenterDB@926] [Read from vcenter VN <ctest-vCenter-55191957, f90106d9-fc85-3c37-a483-bc78ae8fa5a6>, ipPoolId null]
[2018-07-10 12:50:06,144] [ERROR] [Thread-3:VCenterDB@688] [dvSwitch: c4k4_dvs Datacenter: c4_datacenter11 Private VLAN NOTconfigured]
[2018-07-10 12:50:06,144] [ERROR] [Thread-3:VirtualNetworkInfo@277] [VN <c4k4u14_dvpg, 75acac93-6416-38b5-9c24-1b75c0adbea3>Cannot populate vlan, private vlan not configured on dvSwitch: c4k4_dvs Datacenter: c4_datacenter11]