Images service variables should be renamed

[vjrj]

As in #292 the new bie-index-config.yml uses image_base_url instead of images_base_url in plural, so some inventories like living-atlas fails because there is not such variable. See the usage:

$ grep -rc image_base_url ansible | grep -v ":0"
ansible/roles/bie-index/templates/bie-index-config.yml:2
ansible/roles/expert/templates/expert-config.properties:1
ansible/roles/specimenbrowser/templates/specimenbrowser-config.properties:2
$ grep -rc images_base_url ansible | grep -v ":0"
ansible/inventories/vagrant/biocollect-vagrant:1
ansible/inventories/vagrant/dashboard-vagrant:1
ansible/inventories/vagrant/demo-vagrant:1
ansible/inventories/vagrant/expert-vagrant:1
ansible/inventories/vagrant/images-vagrant:1
ansible/inventories/vagrant/merit-vagrant:1
ansible/inventories/vagrant/profiles-vagrant:2
ansible/inventories/workshop/demo-livingatlas.yml:1
ansible/inventories/vagrant_all:2
ansible/inventories/living-atlas:1
ansible/roles/biocollect/templates/biocollect-config.properties:1
ansible/roles/dashboard/templates/dashboard-config.properties:1
ansible/roles/image-service/templates/config/config.properties:4
ansible/roles/image-service/templates/sql/export.sql:2
ansible/roles/merit/templates/fieldcapture-config.properties:1
ansible/roles/profile-hub/templates/profile-hub-config.properties:1
ansible/roles/profile-service/templates/profile-service-config.properties:1

I can send a patch if someone suggest which variable name should be use. Also we can use some double default bie-index-config.yml to search for the two variables and don't break things, like in: https://github.com/AtlasOfLivingAustralia/ala-install/pull/281/commits/4d69dddebe059cfff5e679723487a4ddd9f377ec

just tell me.

[ansell]

Hold off on a patch for this until after the feature/image-service-grails3 branch is merged (or alternatively, develop a patch against that branch)

[vjrj]

I'll wait for the merge to test and patch if necessary. Thanks @ansell