isPortOpen() function doesnt work if scanning udp port

[daffainfo]

UDP port wont be detected when using isPortOpen function because that function only detects TCP port. A small example can be found at https://github.com/projectdiscovery/nuclei-templates/blob/main/javascript/udp/detection/tftp-detect.yaml

When using that template it always return not found even though the host is already using tftp

$ nuclei -u 201.194.192.183 -t nuclei-templates/javascript/udp/detection/tftp-detect.yaml --debug


                     __     _
   ____  __  _______/ /__  (_)
  / __ \/ / / / ___/ / _ \/ /
 / / / / /_/ / /__/ /  __/ /
/_/ /_/\__,_/\___/_/\___/_/   v3.2.9

                projectdiscovery.io

[INF] Current nuclei version: v3.2.9 (latest)
[INF] Current nuclei-templates version: v9.9.1 (latest)
[WRN] Scan results upload to cloud is disabled.
[INF] New templates added in latest release: 75
[INF] Templates loaded for current scan: 1
[INF] Executing 1 signed templates from projectdiscovery/nuclei-templates
[INF] Targets loaded for current scan: 1
[DBG] [tftp-detect] Executing Precondition for request
[DBG]  [tftp-detect] Javascript Code:

        isPortOpen(Host, Port);

[WRN] [tftp-detect] Could not execute request for 201.194.192.183: [tftp-detect:RUNTIME] could not execute pre-condition: dial tcp 201.194.192.183:69: connect: connection refused