chore(config): remove deprecated usehistory setting

The usehistory option is superseded by historykeep and related
settings. Removing this redundant configuration entry.

Author: nmaguiar

mini-a-modes.yaml

@@ -110,7 +110,6 @@ modes:
       mcpproxy   : true
       mcpproxythreshold: 51200
       mcpproxytoon     : true
-      usehistory       : true
       historykeep      : true
       historykeepperiod: 10080
       historykeepcount : 15