Hide BuddyPress widgets on MultiSite install

BuddyPress adding some widgets meant to use for BuddyPress related informations but those widgets are unnecessary for sites in MultiSite unless BuddyPress multiblog is enabled.

add_action( 'bp_include', 'firmasite_bp_include_remove_widgets', 5 ); // priority is crucial
function firmasite_bp_include_remove_widgets() {
  if ( !bp_is_root_blog() && !bp_is_multiblog_mode() )
  	remove_all_actions( 'bp_register_widgets' );
}  

Thanks @geminorum and @BoweFrankema for inspiring this code snippet.