Description:
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Hi there,

there seems to be a bug when using SolrQuery::setGroupLimit().

Under certain circumstances, SolrClient exits with "Solr HTTP Error 56: 'Failure when receiving data from the peer'"
This normally happens, if I reuse a SolrClient-Connection and additionally the returned resultset is smaller than requested by setGroupLimit.

If I omit the "setGroupLimit"-call or if I reinstantiate a new connection no error is shown.

Test script:
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$db = new \SolrClient(['host' => 'localhost', 'path' => 'solr/test']);

$query = new \SolrQuery();
$query->setGroup(true);
$query->addGroupField('testfield_with_many_rs');
$query->setGroupLimit(2);
$db->query($query); // works

$query = new \SolrQuery();
$query->setGroup(true);
$query->addGroupField('testfield_with_one_rs');
$query->setGroupLimit(2);
$db->query($query); // throws Exception

Actual result:
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Solr HTTP Error 56: 'Failure when receiving data from the peer'