Does not place nice with '/' (root) endpoint

[joshnatis]

Hey there, thanks for your great work on this plugin :).

Some weird stuff happens when I try to profile the / endpoint of my app (which happens to be the main endpoint, so I basically can't use the plugin lol). Check it out:

<ul>
    <li><a href="URL/nytprof/nytprof.out..24" "=""></a> (PID 24,Fri May 27 19:24:01 2022,0.2409 secs)</li>
    <li><a href="URL/nytprof/nytprof.out.checkstatus.25" "="">checkstatus</a> (PID 25,Fri May 27 19:20:41 2022,0.0092 secs)</li> 
    <li><a href="URL/nytprof/nytprof.out.swag.28" "="">swag</a> (PID 28,Fri May 27 19:20:36 2022,0.0004 secs)</li>
</ul>

I believe that can be attributed to this line: $path =~ s{^/}{};.

Now that I'm looking at the HTML there seem to be some other issues too. E.g. <a href="URL/nytprof/nytprof.out.checkstatus.25" "="">, not sure what's going on there...

I don't know what the best way to fix this would be, maybe replacing a path consisting only of a / with root? Seems hacky, I don't know if there's any sentinel value we can use that wouldn't conflict with possible endpoint names.