Same port number for Multiple NAT Entries

[nalurihemanth]

While we create a static NAT Entry, It is allowing to create multiple entries with the same Port numbers. This will create a duplicate entry and will be hard to manage incase we by mistake use the previously opened ports to another request.

• phpIPAM version: 1.6
• OS : Ubuntu 16.04 64bit
• PHP version 7.4
• Webserver Apache2
• Database MYSQL