If setting URL to a web server running on a custom port, the port setting is ignored and port 80 is used.
Steps to reproduce:
1. Start a web server on a port that is not port 80, I used port 1025 and a web server running on my local PC. Verify web page displays correctly in browser.
2. In the Custom content plugin, set "Content type" to "web page"
3. Set the "URL" in this gadget to something like "http://localhost:1025/index.html"
4. Start Wireshark and then load the Jira dashboard.
5. In Wireshark it can be seen that the plugin is trying to access the web server on port 80 and ignores the port configured in URL.
If instead setting "Content type" to "Image", the configured port is used and it works as expected.
Running on Win 10x64, version 1803, OS build 17134.376
Using Chrome Version 70.0.3538.77 (Officiell version) (64 bitar)