When using old/faulty DB files, all tables are created by the DBManager

Tables were tested with AND statements, so if a single table was missing, the DBManager considered the input file as empty and started creating all the needed DB tables in that file.

Now, we use OR clauses and even if only one table is present (which should not occur, however) the file is considered non-empty and the creation of the tables is skipped.

added GeoModelDBManager label

closed via commit b974f7b4

Fixed.

marked this issue as related to #6

mentioned in commit b974f7b4