fix fclose error on failed connection

[fritzmg]

See https://github.com/contao/check/pull/107#issuecomment-290184167

I have simply moved fclose to the already existing if ($connected).

[leofeyer]

You can further simplify the code.

Current:

$connected = ($connection !== false);

if ($connected) {
    fclose($connection);
    return true;
}

return false;

Simplified:

if ($connection !== false) {
    fclose($connection);
    return true;
}

return false;

There is no need to define a variable $connected which is only used once.

[fritzmg]

True, done.