Doesn’t allow server port 443

[damomurf]

Presumably because of the nature of the underlying URL function in use, the code reference at

matrix-action/src/index.ts

Line 64 in dbe54a9

return `${serverURL.protocol}//${serverURL.host}:${serverURL.port || 8448}`

doesn’t allow for the specification of port 443 for the matrix home server. If :443 is specified in either https://<host>:443 or <host:443> forms the code replaces the port number with 8448.