Add 'server' to scope_to_string's list of possible suspects, as to avoid an...

Add 'server' to scope_to_string's list of possible suspects, as to avoid an error when LogLevel is trace

git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/trunk@1377457 13f79535-47bb-0310-9956-ffa450edef68