TypeError:
can't convert Symbol into String
# ./lib/casserver/views/proxy_validate.builder:12:in `+'
# ./lib/casserver/views/proxy_validate.builder:12:in `block (5 levels) in singletonclass'
# ./lib/casserver/views/proxy_validate.builder:11:in `each'
# ./lib/casserver/views/proxy_validate.builder:11:in `block (4 levels) in singletonclass'
# ./lib/casserver/views/proxy_validate.builder:10:in `block (3 levels) in singletonclass'
# ./lib/casserver/views/proxy_validate.builder:7:in `block (2 levels) in singletonclass'
# ./lib/casserver/views/proxy_validate.builder:6:in `block in singletonclass'
# ./lib/casserver/views/proxy_validate.builder:65535:in `instance_eval'
# ./lib/casserver/views/proxy_validate.builder:65535:in `singletonclass'
# ./lib/casserver/views/proxy_validate.builder:65533:in `__tilt_15800300'
# ./lib/casserver/server.rb:663:in `block in <class:Server>'
# ./spec/casserver_spec.rb:156:in `block (3 levels) in <top (required)>'
