[idea] tell user about locked table

[odinuv]

test by running e.g.: lock table special in EXCLUSIVE mode; and after some time release the lock with commit;

[ErikZigo]

@odinuv mrkni na to, ja myslim ze se to muze mergnout. DROP TABLE se uz taky loguje do event a doplnil jsem test na ten tvuj check se zamkem

[odinuv]

jo prijde mi to dobry