Remove warnings in HTTP transport for search
Remove warnings in HTTP transport for search

Fixes an undefined variable warning in `ElasticSearch\Transport\HTTP::search()` when no query is specified.
Closes #39
nervetattoo/elasticsearch,1e1/elasticsearch,lammensj/elasticsearch,navnorth/elasticsearch,1e1/elasticsearch,lammensj/elasticsearch,nervetattoo/elasticsearch,navnorth/elasticsearch