should we raise exception upon invalid @docinfo_target ?

[colinsurprenant]

Per discussion with @guyboertje in PR #35 #35 (comment)

It seems that raising exception in this context is rather extreme? see

logstash-input-elasticsearch/lib/logstash/inputs/elasticsearch.rb

Lines 178 to 183 in a8692e3

	unless docinfo_target.is_a?(Hash)
	@logger.error("Elasticsearch Input: Incompatible Event, incompatible type for the docinfo_target=#{@docinfo_target} field in the `_source` document, expected a hash got:", :docinfo_target_type => docinfo_target.class, :event => event)
	# TODO: (colin) I am not sure raising is a good strategy here?
	raise Exception.new("Elasticsearch input: incompatible event")
	end