settings: Send config_data to bot update API only if required.
settings: Send config_data to bot update API only if required.

There is config_data for the embedded bots only for giphy and
followup bots, so we send "config_data" field to API only for
those bots and not others. Send config_data field as {} to
the API for other bots raised InternalError earlier.

andersk/zulip,andersk/zulip,kou/zulip,rht/zulip,andersk/zulip,andersk/zulip,andersk/zulip,rht/zulip,rht/zulip,rht/zulip,andersk/zulip,zulip/zulip,zulip/zulip,kou/zulip,zulip/zulip,zulip/zulip,kou/zulip,zulip/zulip,zulip/zulip,rht/zulip,kou/zulip,kou/zulip,rht/zulip,andersk/zulip,rht/zulip,kou/zulip,zulip/zulip,kou/zulip