Disabled completion lockout in mod_query

This fixes a bug in query_lua where consecutive completions would never happen
if mod_query.autoshowcompl was enabled.

To trigger the bug, invoke binding that calls

 mod_query.query_lua()

Then type "ionco" and press TAB. mod_query then completes this to "ioncore.". At
this point the completion should happen again, and the various
methods/properties of ioncore should be displayed. This does not happen.
Pressing TAB again doesn't work either. One actually has to delete the "." and
re-type it.

This was happening because the second completion was being blocked. I THINK this
was trying to prevent a timer re-entrancy. However everything is synchronous, so
this couldn't happen anyway.