Broken link for fancy tag names with @

[szpak]

For example for this tag:
https://github.com/jorgebucaran/hyperapp/releases/tag/@hyperapp/events@0.0.4
(https://github.com/jorgebucaran/hyperapp/releases/tag/%40hyperapp%2Fevents%400.0.4)

an URL generated in the mail notification is:
https://github.com/jorgebucaran/hyperapp/releases/tag/events@0.0.4

Probably some filter strips out @foo/ from a tag name.