Fix typo in http-client component composer.json

Author: igorw

composer.json

@@ -7,7 +7,7 @@
         "php": ">=5.3.3",
         "guzzle/http": "2.8.*",
         "guzzle/parser": "2.8.*",
-        "react/socket": "0.2.*"
+        "react/socket": "0.2.*",
         "react/dns": "0.2.*"
     },
     "autoload": {