Prefer frozen empty string.

Author: ioquatix

lib/async/http/faraday/adapter.rb

@@ -241,7 +241,7 @@ def with_timeout(task: Async::Task.current)
 
 				def encoded_body(response)
 					body = response.read
-					return +"" if body.nil?
+					return "" if body.nil?
 					content_type = response.headers["content-type"]
 					return body unless content_type
 					params = extract_type_parameters(content_type)