Don't show stack trace when unknown exception happens during login.
Don't show stack trace when unknown exception happens during login.

Fixes bug 951799

Change-Id: Ib012a75e5b0e1d40aab590ecc37a72c3c2ff1343

endorphinl/horizon,icloudrnd/automation_tools,django-leonardo/horizon,CiscoSystems/horizon,NeCTAR-RC/horizon,CiscoSystems/avos,openstack-ja/horizon,sandvine/horizon,xinwu/horizon,mrunge/horizon_lib,takeshineshiro/horizon,r-icarus/openstack_microserver,luhanhan/horizon,kaiweifan/horizon,karthik-suresh/horizon,NCI-Cloud/horizon,luhanhan/horizon,endorphinl/horizon,gerrive/horizon,mdavid/horizon,r-icarus/openstack_microserver,doug-fish/horizon,spring-week-topos/horizon-week,mrunge/horizon_lib,RudoCris/horizon,j4/horizon,icloudrnd/automation_tools,redhat-openstack/horizon,VaneCloud/horizon,CiscoSystems/avos,wangxiangyu/horizon,coreycb/horizon,CiscoSystems/avos,Daniex/horizon,Hodorable/0602,openstack/horizon,damien-dg/horizon,doug-fish/horizon,occ-data/tukey-portal,redhat-cip/horizon,pranavtendolkr/horizon,zouyapeng/horizon,Tesora/tesora-horizon,promptworks/horizon,ging/horizon,tellesnobrega/horizon,BiznetGIO/horizon,philoniare/horizon,karthik-suresh/horizon,doug-fish/horizon,citrix-openstack-build/horizon,FNST-OpenStack/horizon,openstack/horizon,Hodorable/0602,maestro-hybrid-cloud/horizon,wolverineav/horizon,kfox1111/horizon,VaneCloud/horizon,LabAdvComp/tukey_portal,tqtran7/horizon,openstack-ja/horizon,nvoron23/avos,watonyweng/horizon,promptworks/horizon,redhat-cip/horizon,kaiweifan/horizon,ChameleonCloud/horizon,idjaw/horizon,vbannai/disk-qos-horizon,xinwu/horizon,flochaz/horizon,yjxtogo/horizon,django-leonardo/horizon,wolverineav/horizon,dan1/horizon-proto,netscaler/horizon,opencloudconsortium/tukey-portal,watonyweng/horizon,NCI-Cloud/horizon,Daniex/horizon,dan1/horizon-proto,coreycb/horizon,LabAdvComp/tukey_portal,r-icarus/openstack_microserver,1ukash/horizon,dan1/horizon-x509,mandeepdhami/horizon,JioCloud/horizon,Metaswitch/horizon,anthonydillon/horizon,Frostman/eho-horizon,vbannai/disk-qos-horizon,wangxiangyu/horizon,yeming233/horizon,endorphinl/horizon-fork,99cloud/keystone_register,Dark-Hacker/horizon,sandvine/horizon,kfox1111/horizon,Solinea/horizon,savi-dev/horizon,VaneCloud/horizon,ging/horizon,yanheven/console,Solinea/horizon,Dark-Hacker/horizon,orbitfp7/horizon,mrunge/horizon,doug-fish/horizon,yjxtogo/horizon,NeCTAR-RC/horizon,CiscoSystems/horizon,kfox1111/horizon,froyobin/horizon,ikargis/horizon_fod,tsufiev/horizon,nvoron23/avos,tqtran7/horizon,gerrive/horizon,pranavtendolkr/horizon,gerrive/horizon,Metaswitch/horizon,django-leonardo/horizon,maestro-hybrid-cloud/horizon,Mirantis/mos-horizon,asomya/test,Tesora/tesora-horizon,karthik-suresh/horizon,endorphinl/horizon-fork,eayunstack/horizon,tellesnobrega/horizon,izadorozhna/dashboard_integration_tests,noironetworks/horizon,xme1226/horizon,liyitest/rr,mdavid/horizon,maestro-hybrid-cloud/horizon,pranavtendolkr/horizon,anthonydillon/horizon,watonyweng/horizon,Metaswitch/horizon,BiznetGIO/horizon,henaras/horizon,spring-week-topos/horizon-week,mdavid/horizon,opencloudconsortium/tukey-portal,tellesnobrega/horizon,Mirantis/mos-horizon,philoniare/horizon,j4/horizon,tsufiev/horizon,liyitest/rr,Dark-Hacker/horizon,yeming233/horizon,davidcusatis/horizon,coreycb/horizon,anthonydillon/horizon,yjxtogo/horizon,newrocknj/horizon,BiznetGIO/horizon,aaronorosen/horizon-congress,asomya/test,xinwu/horizon,mdavid/horizon,luhanhan/horizon,Mirantis/mos-horizon,ikargis/horizon_fod,agileblaze/OpenStackTwoFactorAuthentication,Dark-Hacker/horizon,BiznetGIO/horizon,Tesora/tesora-horizon,RudoCris/horizon,pranavtendolkr/horizon,bigswitch/horizon,sandvine/horizon,vladryk/horizon,tanglei528/horizon,xinwu/horizon,bac/horizon,CiscoSystems/horizon,karthik-suresh/horizon,Tesora/tesora-horizon,endorphinl/horizon,philoniare/horizon,henaras/horizon,ikargis/horizon_fod,netscaler/horizon,Hodorable/0602,yjxtogo/horizon,mrunge/openstack_horizon,openstack/horizon,spring-week-topos/horizon-week,occ-data/tukey-portal,bigswitch/horizon,Solinea/horizon,maestro-hybrid-cloud/horizon,vbannai/disk-qos-horizon,watonyweng/horizon,django-leonardo/horizon,dan1/horizon-proto,redhat-openstack/horizon,saydulk/horizon,VaneCloud/horizon,tanglei528/horizon,henaras/horizon,tuskar/tuskar-ui,noironetworks/horizon,savi-dev/horizon,Hodorable/0602,liyitest/rr,redhat-openstack/horizon,mrunge/horizon,yeming233/horizon,endorphinl/horizon-fork,newrocknj/horizon,aaronorosen/horizon-congress,dan1/horizon-x509,noironetworks/horizon,tanglei528/horizon,1ukash/horizon,flochaz/horizon,nvoron23/avos,blueboxgroup/horizon,flochaz/horizon,orbitfp7/horizon,JioCloud/horizon,rdo-management/tuskar-ui,ChameleonCloud/horizon,agileblaze/OpenStackTwoFactorAuthentication,wangxiangyu/horizon,dan1/horizon-proto,newrocknj/horizon,kaiweifan/horizon,vladryk/horizon,dan1/horizon-x509,davidcusatis/horizon,redhat-cip/horizon,damien-dg/horizon,saydulk/horizon,wangxiangyu/horizon,mandeepdhami/horizon,ging/horizon,Daniex/horizon,NCI-Cloud/horizon,99cloud/keystone_register,luhanhan/horizon,RudoCris/horizon,tuskar/tuskar-ui,endorphinl/horizon-fork,newrocknj/horizon,openstack-ja/horizon,izadorozhna/dashboard_integration_tests,rdo-management/tuskar-ui,mandeepdhami/horizon,idjaw/horizon,1ukash/horizon,rickerc/horizon_audit,promptworks/horizon,Solinea/horizon,takeshineshiro/horizon,blueboxgroup/horizon,gerrive/horizon,mrunge/openstack_horizon,redhat-cip/horizon,bac/horizon,froyobin/horizon,davidcusatis/horizon,FNST-OpenStack/horizon,idjaw/horizon,j4/horizon,openstack/horizon,icloudrnd/automation_tools,tsufiev/horizon,gochist/horizon,occ-data/tukey-portal,blueboxgroup/horizon,nvoron23/avos,eayunstack/horizon,takeshineshiro/horizon,tellesnobrega/horizon,dan1/horizon-x509,blueboxgroup/horizon,mrunge/openstack_horizon,LabAdvComp/tukey_portal,saydulk/horizon,yanheven/console,FNST-OpenStack/horizon,j4/horizon,davidcusatis/horizon,froyobin/horizon,asomya/test,saydulk/horizon,LabAdvComp/tukey_portal,damien-dg/horizon,Mirantis/mos-horizon,bigswitch/horizon,bigswitch/horizon,zouyapeng/horizon,coreycb/horizon,damien-dg/horizon,flochaz/horizon,zouyapeng/horizon,NeCTAR-RC/horizon,henaras/horizon,NCI-Cloud/horizon,promptworks/horizon,wolverineav/horizon,agileblaze/OpenStackTwoFactorAuthentication,opencloudconsortium/tukey-portal,99cloud/keystone_register,ChameleonCloud/horizon,Frostman/eho-horizon,Frostman/eho-horizon,orbitfp7/horizon,anthonydillon/horizon,savi-dev/horizon,JioCloud/horizon,rdo-management/tuskar-ui,FNST-OpenStack/horizon,bac/horizon,rdo-management/tuskar-ui,citrix-openstack-build/horizon,Metaswitch/horizon,kfox1111/horizon,rickerc/horizon_audit,liyitest/rr,redhat-openstack/horizon,idjaw/horizon,rickerc/horizon_audit,sandvine/horizon,tqtran7/horizon,vladryk/horizon,yanheven/console,icloudrnd/automation_tools,CiscoSystems/avos,agileblaze/OpenStackTwoFactorAuthentication,citrix-openstack-build/horizon,mandeepdhami/horizon,bac/horizon,RudoCris/horizon,wolverineav/horizon,ging/horizon,NeCTAR-RC/horizon,tqtran7/horizon,yeming233/horizon,vladryk/horizon,tuskar/tuskar-ui,zouyapeng/horizon,eayunstack/horizon,orbitfp7/horizon,philoniare/horizon,gochist/horizon,tsufiev/horizon,gochist/horizon,mrunge/horizon_lib,mrunge/horizon,xme1226/horizon,Daniex/horizon,xme1226/horizon,netscaler/horizon,noironetworks/horizon,ChameleonCloud/horizon,aaronorosen/horizon-congress,CiscoSystems/horizon,endorphinl/horizon,takeshineshiro/horizon