testing/althttpd: upgrade to 202012121322
Upstream commit comment: Add in the REQUEST_SCHEMA environment variable for compatibility with Apache. See https://www.fossil-scm.org/forum/forumpost/cb17013d06
Upstream commit comment: Add in the REQUEST_SCHEMA environment variable for compatibility with Apache. See https://www.fossil-scm.org/forum/forumpost/cb17013d06