bin/tnrs_db: removed no longer used $wait flag (which caused tnrs_db to wait max_pause for new rows to be added), because tnrs_db is now invoked automatically after each import by the import_scrub target (in inputs/input.Makefile) and does not need to run as a daemon. note that when scrub is invoked, it is possible that a previous datasource's import has already scrubbed the names for this import, because tnrs_db runs until all rows in tnrs_input_name are scrubbed.

this also removes clutter in tnrs_db, making it clearer what operations it performs that the library function tnrs.repeated_tnrs_request() does not (namely, interfacing with the DB and profiling the TNRS request).