Fix string substitution for spring_profiles
in login.yml.erb

Currently, in order to get the result
spring_profiles: saml
the workaround is to set
properties.login.spring_profiles: ldap,saml

https://www.pivotaltracker.com/story/show/77895154
[#77895154]
set default for spring_profiles property
Allows the properties.login.spring_profiles property to come from an outside manifest to be merged in.
Merge remote-tracking branch 'origin/pr/494' into develop