Make this easier to read
[mms] Fix AllTests.php when dealing with test cases that inherit from parent test cases.
There is no need to add imap.so explicitly

AFAICT, this file is for adding extensions installed via PECL. If an
extension is built-in to PHP, it will already be defined in the master
php.ini file.  (This fixes about a billion errors on 5.4 and 5.5 builds
since imap.so doesn't exist there).