Revert "PLT-2183 Slash command auto-complete"

webapp/utils/constants.jsx

@@ -595,10 +595,6 @@ export default {
         EMBED_TOGGLE: {
             label: 'embed_toggle',
             description: 'Show toggle for all embed previews'
-        },
-        SLASHCMD_AUTOCMP: {
-            label: 'slashCmd_autocmp',
-            description: 'Enable external application to offer slash command autocomplete'
         }
     },
     OVERLAY_TIME_DELAY: 400,