Reporting error when verbose flag is on

[Stefano Lenzi]

If the option --verbose is set in variable OPTS the autopostgresqlbackup sends an email with "ERROR REPORTED" even if there is no error at all. The reason is that the --verbose option of pg_dump sends the verbose output to the STDERR.

I have attached an update version of the script which avoid to send message if pg_dump report no error (by using the exit code instead of the STDERR output)

Moreover the attached version uses a LOGDBG variable for storing debug message of the autopostgresqlbackup script itself, when LOGDBG is empty no log is debug message is saved.