Fix get_input_* not skipping None entities (#215)
Fix get_input_* not skipping None entities (#215)

This was an issue when parsing optional parameters, since None
could not be specified, resulting in a strange crash.

LonamiWebs/Telethon,andr-04/Telethon,LonamiWebs/Telethon,LonamiWebs/Telethon,LonamiWebs/Telethon,expectocode/Telethon