Description:
------------
While migrating our application from PHP 7.2 to PHP 7.3, we noticed that some `docx` files report a duplicate mime type. It looks like the fix committed in https://github.com/php/php-src/commit/d874d4a15c2e17a753d580691906c95e9153b823 is the one that introduces this issue, previous commits don't expose this issue.

The below builds are compiled with: ./configure --disable-all --enable-fileinfo && make
Switched to a new branch 'ee50461'
./sapi/cli/php ../payload.php
application/vnd.openxmlformats-officedocument.wordprocessingml.document

Switched to a new branch 'd874d4a'
./sapi/cli/php ../payload.php
application/vnd.openxmlformats-officedocument.wordprocessingml.documentapplication/vnd.openxmlformats-officedocument.wordprocessingml.document

Test script:
---------------
<?php
// You can grab a copy of this file in https://www.buayacorp.com/demo.docx (it's an empty Google doc file saved as "docx" format).
$filename = __DIR__ . '/demo.docx';
$finfo = finfo_open(FILEINFO_MIME_TYPE);
echo finfo_file($finfo, $filename).PHP_EOL;
finfo_close($finfo);

Expected result:
----------------
application/vnd.openxmlformats-officedocument.wordprocessingml.document

Actual result:
--------------
application/vnd.openxmlformats-officedocument.wordprocessingml.documentapplication/vnd.openxmlformats-officedocument.wordprocessingml.document