add psql option no-psqlrc

[aoberest]

Hello.
Thanks for your script.

I have custom command in ~/.psqlrc file.
When i run zabbix-dump script I receive error.

Starting table backups...
./zabbix-dump: line 555: /var/lib/pgsql/11/backups/zabbix_cfg_host_20200731-0752_db-psql-Expanded display is off.
Output format is wrapped.
Timing is on.

and

  4.4.2.sql: File name too long

ERROR: Could not backup database.

Please, add options "--no-psqlrc" for psql command.

--no-psqlrc Do not read the start-up file (neither the system-wide psqlrc file nor the user's ~/.psqlrc file)