Fix type mismatch errors in NetworkTestCase
Fix type mismatch errors in NetworkTestCase

A few tests of NetworkTestCase use string literals as
network_id values. This works great when running tests
on both SQLite and MySQL, but fails on PostgreSQL, which
is very string when checking data types.

Blueprint: db-api-tests-on-all-backends

Change-Id: I090e42ff045379ac404e7bc5c91fbc82a52920b0

TwinkleChawla/nova,maelnor/nova,hanlind/nova,spring-week-topos/nova-week,orbitfp7/nova,scripnichenko/nova,whitepages/nova,ewindisch/nova,vmturbo/nova,isyippee/nova,tianweizhang/nova,projectcalico/calico-nova,fnordahl/nova,noironetworks/nova,virtualopensystems/nova,saleemjaveds/https-github.com-openstack-nova,alaski/nova,devendermishrajio/nova_test_latest,iuliat/nova,dawnpower/nova,CloudServer/nova,akash1808/nova_test_latest,j-carpentier/nova,blueboxgroup/nova,leilihh/novaha,gooddata/openstack-nova,zhimin711/nova,Juniper/nova,j-carpentier/nova,shail2810/nova,devendermishrajio/nova,CiscoSystems/nova,adelina-t/nova,eonpatapon/nova,ruslanloman/nova,Metaswitch/calico-nova,CCI-MOC/nova,CCI-MOC/nova,luogangyi/bcec-nova,vmturbo/nova,Francis-Liu/animated-broccoli,tanglei528/nova,watonyweng/nova,rrader/nova-docker-plugin,akash1808/nova,tangfeixiong/nova,redhat-openstack/nova,cloudbase/nova-virtualbox,double12gzh/nova,fnordahl/nova,eharney/nova,CEG-FYP-OpenStack/scheduler,TwinkleChawla/nova,bigswitch/nova,rajalokan/nova,gooddata/openstack-nova,berrange/nova,varunarya10/nova_test_latest,orbitfp7/nova,double12gzh/nova,Juniper/nova,JioCloud/nova_test_latest,yosshy/nova,sebrandon1/nova,tanglei528/nova,redhat-openstack/nova,mgagne/nova,thomasem/nova,cloudbase/nova-virtualbox,eonpatapon/nova,cernops/nova,tianweizhang/nova,scripnichenko/nova,zzicewind/nova,ewindisch/nova,alaski/nova,jianghuaw/nova,CloudServer/nova,rajalokan/nova,sacharya/nova,silenceli/nova,joker946/nova,luogangyi/bcec-nova,joker946/nova,leilihh/novaha,watonyweng/nova,jeffrey4l/nova,Francis-Liu/animated-broccoli,openstack/nova,petrutlucian94/nova,shahar-stratoscale/nova,klmitch/nova,petrutlucian94/nova_dev,klmitch/nova,Yusuke1987/openstack_template,mikalstill/nova,NeCTAR-RC/nova,devoid/nova,Juniper/nova,adelina-t/nova,MountainWei/nova,phenoxim/nova,edulramirez/nova,takeshineshiro/nova,belmiromoreira/nova,OpenAcademy-OpenStack/nova-scheduler,eayunstack/nova,projectcalico/calico-nova,leilihh/nova,devoid/nova,devendermishrajio/nova,affo/nova,bigswitch/nova,kimjaejoong/nova,mandeepdhami/nova,isyippee/nova,tealover/nova,zaina/nova,ted-gould/nova,petrutlucian94/nova,mikalstill/nova,zhimin711/nova,rrader/nova-docker-plugin,rahulunair/nova,alvarolopez/nova,zaina/nova,yatinkumbhare/openstack-nova,akash1808/nova,mikalstill/nova,mahak/nova,JianyuWang/nova,spring-week-topos/nova-week,angdraug/nova,silenceli/nova,cernops/nova,hanlind/nova,takeshineshiro/nova,alexandrucoman/vbox-nova-driver,shail2810/nova,jeffrey4l/nova,dawnpower/nova,vladikr/nova_drafts,Stavitsky/nova,gooddata/openstack-nova,tudorvio/nova,eayunstack/nova,dims/nova,vladikr/nova_drafts,badock/nova,BeyondTheClouds/nova,alexandrucoman/vbox-nova-driver,vmturbo/nova,rahulunair/nova,mahak/nova,Tehsmash/nova,JianyuWang/nova,mandeepdhami/nova,barnsnake351/nova,Tehsmash/nova,cloudbase/nova,MountainWei/nova,jianghuaw/nova,angdraug/nova,gooddata/openstack-nova,jianghuaw/nova,felixma/nova,mahak/nova,akash1808/nova_test_latest,rahulunair/nova,sebrandon1/nova,Juniper/nova,tudorvio/nova,iuliat/nova,saleemjaveds/https-github.com-openstack-nova,apporc/nova,mmnelemane/nova,kimjaejoong/nova,noironetworks/nova,OpenAcademy-OpenStack/nova-scheduler,yatinkumbhare/openstack-nova,rajalokan/nova,JioCloud/nova_test_latest,mmnelemane/nova,sebrandon1/nova,openstack/nova,viggates/nova,bgxavier/nova,tangfeixiong/nova,felixma/nova,berrange/nova,phenoxim/nova,mgagne/nova,nikesh-mahalka/nova,NeCTAR-RC/nova,thomasem/nova,jianghuaw/nova,cyx1231st/nova,eharney/nova,varunarya10/nova_test_latest,openstack/nova,LoHChina/nova,cloudbase/nova,belmiromoreira/nova,CEG-FYP-OpenStack/scheduler,Stavitsky/nova,BeyondTheClouds/nova,ruslanloman/nova,hanlind/nova,rajalokan/nova,affo/nova,whitepages/nova,vmturbo/nova,badock/nova,devendermishrajio/nova_test_latest,alvarolopez/nova,petrutlucian94/nova_dev,Metaswitch/calico-nova,cyx1231st/nova,tealover/nova,shahar-stratoscale/nova,apporc/nova,raildo/nova,leilihh/nova,BeyondTheClouds/nova,ted-gould/nova,sacharya/nova,JioCloud/nova,cloudbase/nova,viggates/nova,yosshy/nova,CiscoSystems/nova,klmitch/nova,klmitch/nova,cernops/nova,blueboxgroup/nova,virtualopensystems/nova,dims/nova,zzicewind/nova,nikesh-mahalka/nova,bgxavier/nova,edulramirez/nova,raildo/nova,JioCloud/nova,barnsnake351/nova,maelnor/nova,Yusuke1987/openstack_template,LoHChina/nova