Win32: The filename validity checker now allows "COM" but refuses access

to "COM1" through "COM4". This allows filenames such as "com.name" to be
served. If was supposed to work like this but a bug meant that the "COM1"
invalid filename was matching "COM". Similarly the check for "LPT1" would
have denied access to filenames with a "LPT" segment.
PR: 3769


git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/branches/1.3.x@82732 13f79535-47bb-0310-9956-ffa450edef68