www/shellinabox: Restore port until sysutils/ttyd is fixed

sysutils/ttyd failed for me on several systems and upstream
didn't respond.

Users should have a working implementation of shell-in-a-browser
therefore it's better to keep shellinabox until issues are resolved.

This reverts commit d3542c47ef9d6fde36bbbc9f73e723ca0d610557.