#8797 changed mailers from using *_url helpers to *_path, and relied on Roadie's URL rewriting to change them to full URLs. This works reliably and avoids needing to repeat URL options, but it throws deprecation warnings and will not work in Rails 5.

Running host_mailer_test generates warnings such as:

DEPRECATION WARNING: The method `host_path` cannot be used here as a full URL is required. Use `host_url` instead. (called from app_views_host_mailer_link_to_host_html_erb__4138992061028702271_130918480 at /home/dcleal/code/foreman/foreman/app/views/host_mailer/_link_to_host.html.erb:2)

The change could probably be mostly reverted, and default_url_options used in the mailer to avoid the repetition of URL options.