BUG/MINOR: applet: Always expect data when CLI is waiting for a new command

BUG/MINOR: applet: Always expect data when CLI is waiting for a new command

There is a mechanism for applets to disable the read timeout on the opposite
side if it is now waiting for any data. Of course, there is also a way to
re-activate it. But, it must excplicitly be handle by applets.

For the CLI, some commands may state no input data are expected. So we must
be sure to reset its state when the applet is waiting for a new command. For
now, it is not a bug because no CLI command uses this mechanism.

This patch must be backported to 2.8.