Deadlock on Solr cloud request causing 'Too many open files' error

Hi there,

We are seeing an issue about deadlock on Solr cloud request. 

Say we have a collection with one shard and two replicas for that shard. For whatever reason the cluster appears to be active but each individual replica is down. And when a request comes in, Solr (replica 1) tries to find a remote node (replica 2) to handle the request since the local core (replica 1) is down and when the other node (replica 2) receives the request it does the same to forward the request back to the original node (replica 1). This causes deadlock and eventually uses all the socket causing `Too many open files`.

Not sure what the purpose of finding an inactive node to handle request in HttpSolrCall.getRemoteCoreUrl but taking that out seems to fix the problem