MAINT: lib/bot: remove delete_message flag
MAINT: lib/bot: remove delete_message flag

obsolete with 393529002a62a5b2a295379fb18b5b40649213df

certtools/intelmq,aaronkaplan/intelmq,certtools/intelmq,certtools/intelmq,aaronkaplan/intelmq,aaronkaplan/intelmq