Command autocomplete overrides command history navigation

The command autocompletion tries too much to be helpful and overrides going back and forth in the chat history.

Example: command key, give @p stone, Enter, command key, up arrow

Expected: Getting a stone, then having chat open with "/give @p stone" in the text box.

Actual result: Getting a stone, then having chat open with "/" and a suggested "xp" in it.

This prevents quickly going back a few entries in the last executed commands list.