Fix how we update requirements.txt
Fix how we update requirements.txt

Currently, running sources-branch-updater.sh results in a
requirements.txt that looks like this:

pip==8.0.3 setuptools==20.2.2 wheel==0.29.0
setuptools==20.1.1
wheel==0.29.0

This is because at the top of the script we overwrite IFS and then at
the bottom we do not correctly loop over $PIP_CURRENT_OPTIONS.

This commit simply unsets IFS at the bottom so the loop can properly
iterate over $PIP_CURRENT_OPTIONS.

Change-Id: I16cc7070560f8e80b410cf5bf58675cb3f35e09a

cloudnull/os-ansible-deployment,os-cloud/os-ansible-deployment,cfarquhar/openstack-ansible,robb-romans/openstack-ansible,mrda/openstack-ansible,cfarquhar/openstack-ansible,mancdaz/openstack-ansible,mancdaz/openstack-ansible,stackforge/os-ansible-deployment,major/openstack-ansible,weezer/openstack-ansible,robb-romans/openstack-ansible,BjoernT/os-ansible-deployment,yanyao/openstack-ansible,bunchc/openstack-ansible,BjoernT/openstack-ansible,yanyao/newton,os-cloud/os-ansible-deployment,BjoernT/openstack-ansible,yanyao/newton,Logan2211/openstack-ansible,BjoernT/os-ansible-deployment,Logan2211/openstack-ansible,stackforge/os-ansible-deployment,bunchc/openstack-ansible,yanyao/openstack-ansible,mrda/openstack-ansible,mrda/openstack-ansible,openstack/openstack-ansible,major/openstack-ansible,BjoernT/os-ansible-deployment,weezer/openstack-ansible,major/os-ansible-deployment,openstack/openstack-ansible,cloudnull/os-ansible-deployment,major/os-ansible-deployment