Revert "Dynamically set WordPress WP_HOME & WP_SITEURL"

This reverts commit ad92117d08fe7c71a1bf7d4351ed96e35b4104bd.
WordPress: Remove trailing slash from DPLA_FRONTEND_URL
Merge pull request #32 from dpla/revert-wp-config-variables

Revert "Dynamically set WordPress WP_HOME & WP_SITEURL"