Hello Nikola,
This command should have worked from CLI:
snmp set -v 2c -c private 127.0.0.1 .1.3.6.1.4.1.17713.21.4.7.0 s "ftp://ftpuser:ftppasswd@ftpserverip/ePMP-GPS_Synced-v3.2.tar.gz"
but it appears we may have an issue with CLI, as it is reporting that syntax error. We will have to look into that.
An alternative is to use snmp facility from a Linux PC. In such case, the following command should work:
snmpset -v 2c -c private deviceip .1.3.6.1.4.1.17713.21.4.7.0 s "ftp://ftpuser:ftppasswd@ftpserverip/ePMP-NonGPS_Synced-v3.5.2-RC10.tar.gz"
Regards