Update dependency on async-pool.

Author: ioquatix

async-http.gemspec

@@ -26,7 +26,7 @@ Gem::Specification.new do |spec|
 
 	spec.add_dependency "async", ">= 1.25"
 	spec.add_dependency "async-io", ">= 1.28"
-	spec.add_dependency "async-pool", ">= 0.2"
+	spec.add_dependency "async-pool", ">= 0.6.1"
 	spec.add_dependency "protocol-http", "~> 0.26.0"
 	spec.add_dependency "protocol-http1", "~> 0.19.0"
 	spec.add_dependency "protocol-http2", "~> 0.16.0"