JSON body fix in examples/http_server.rb

Author: Ginja

examples/http_server.rb

@@ -125,7 +125,7 @@ def template(args, server_context:)
 
   # Log the MCP response details
   _, _, body = response
-  if body.is_a?(Array) && !body.empty?
+  if body.is_a?(Array) && !body.empty? && body.first
     begin
       parsed_response = JSON.parse(body.first)
       if parsed_response["error"]