Fix a segfault because ap_method_registry_init() was never called unless

ap_method_register() was called [ie, unless mod_dav was installed]

Reported by: Brian Pane


git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/trunk@94156 13f79535-47bb-0310-9956-ffa450edef68