Fix get_plugin_packages when multiple plugins are in use
Fix get_plugin_packages when multiple plugins are in use

Due to missing space no plugin packages are installed in this case.

Change-Id: I56b105510e4d31a411f2531fdb20c4ddf1ebff20
Closes-Bug: #1530675

samgoon/devstack,noironetworks/devstack,richliu/devstack,dirkmueller/devstack,dtroyer/devstack,openstack-dev/devstack,mssumanth/devstack,bigswitch/devstack,Mahito/devstack,group-policy/devstack,richliu/devstack,mssumanth/devstack,samgoon/devstack,noironetworks/devstack,dirkmueller/devstack,openstack-dev/devstack,group-policy/devstack,bigswitch/devstack,avvocatodemarchis/devstack,Mahito/devstack,bswartz/devstack,avvocatodemarchis/devstack,nawawi/openstack,dtroyer/devstack,nawawi/openstack,bswartz/devstack