Fix a problem in mod_include when we reached the BYTE_COUNT_THRESHOLD

after parsing the first part of the tag.  We could get errors like

[error] [client 127.0.0.1] unknown directive "<!" in parsed doc filename


git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/trunk@90303 13f79535-47bb-0310-9956-ffa450edef68