Support multiple placeholder url tokens

[stlava]

Allows for having multiple tokens in secondary url.

For example:

go link: go/foo/111/222
secondary url: https://example.com/abc/%s/def/%s
result: https://example.com/abc/111/def/222

go link: go/foo/111/222/333
secondary url: https://example.com/abc/%s/def/%s
result: https://example.com/abc/111/def/222/333

go link: go/foo/111
secondary url: https://example.com/abc/%s/def/%s
result: 400 error (more %s than tokens)

[masterginger]

I've been looking for this feature for a long time :)