Aggs: geo_bounds don't like when the lat or lon is equal to 0

[jpountz]

Here is a reproduction:

DELETE test 

PUT test 
{
  "mappings": {
    "test": {
      "properties": {
        "loc": {
          "type": "geo_point"
        }
      }
    }
  }
}

PUT test/test/1
{
  "loc": "1,0"
}

GET test/_search
{
  "aggs": {
    "loc_bounds": {
      "geo_bounds": {
        "field": "loc"
      }
    }
  }
}

which returns

{
   "took": 2,
   "timed_out": false,
   "_shards": {
      "total": 5,
      "successful": 5,
      "failed": 0
   },
   "hits": {
      "total": 1,
      "max_score": 1,
      "hits": [
         {
            "_index": "test",
            "_type": "test",
            "_id": "1",
            "_score": 1,
            "_source": {
               "loc": "1,0"
            }
         }
      ]
   },
   "aggregations": {
      "loc_bounds": {
         "bounds": {
            "top_left": {
               "lat": 1,
               "lon": "Infinity"
            },
            "bottom_right": {
               "lat": 1,
               "lon": "-Infinity"
            }
         }
      }
   }
}