[HttpClient] use "idle" instead of "inactivity" when telling about the timeout option

Author: nicolas-grekas

DependencyInjection/Configuration.php

@@ -1348,7 +1348,7 @@ private function addHttpClientSection(ArrayNodeDefinition $rootNode)
                                     ->info('A comma separated list of hosts that do not require a proxy to be reached.')
                                 ->end()
                                 ->floatNode('timeout')
-                                    ->info('Defaults to "default_socket_timeout" ini parameter.')
+                                    ->info('The idle timeout, defaults to the "default_socket_timeout" ini parameter.')
                                 ->end()
                                 ->scalarNode('bindto')
                                     ->info('A network interface name, IP address, a host name or a UNIX socket to bind to.')