Description:
------------
I'am using the http extension (2.0.6).

If ONE http\Exception\RuntimeException occurs during a call with multiple http\Client::send ALL queries do not call the callback.

If the request on error does not call the callback that can understand this, but ALL the others do not call their own callback, then I think it's a bug.

Test script:
---------------
$urls = ['http://www.google.fr', 'http://www.google.com', 'http://www.notexist.think', 'http://yahoo.com'];
$httpClient = new \http\client();
foreach ($urls as $url) {
    $httpRequest = new \http\Client\Request('GET', $url);
    $httpRequest->setOptions(['redirect' => 10, 'postredir' => \http\Client\Curl\POSTREDIR_ALL]);
    $httpClient->enqueue($httpRequest, function($r){var_dump('callback '.$r->getTransferInfo('effective_url'));return true;});
}
try {
    $httpClient->send();
} catch (\Exception $e) {
    var_dump($e->getMessage());
}

Expected result:
----------------
string(30) "callback http://www.google.fr/"
string(31) "callback http://www.google.com/"
string(35) "callback https://fr.yahoo.com/?p=us"
string(42) "Could not resolve host: www.notexist.think"

OR

string(30) "callback http://www.google.fr/"
string(31) "callback http://www.google.com/"
string(35) "callback https://fr.yahoo.com/?p=us"
string(9) "callback "
string(42) "Could not resolve host: www.notexist.think"

Actual result:
--------------
string(42) "Could not resolve host: www.notexist.think"