main: simplify net/http/pprof routes
main: simplify net/http/pprof routes

pprof.Index reads:

	Index responds with the pprof-formatted profile named by the
	request. For example, "/debug/pprof/heap" serves the "heap"
	profile. Index responds to a request for "/debug/pprof/" with an
	HTML page listing the available profiles.

In other words, sending all /debug/pprof/* requests to it is enough - we
don't have to add specific routes for all the kinds of profiles.

Verified that it still works by requesting /debug/pprof/heap before and
after this patch.

mvdan/tyk,mvdan/tyk,lonelycode/tyk,mvdan/tyk,mvdan/tyk,mvdan/tyk,lonelycode/tyk,lonelycode/tyk,mvdan/tyk,mvdan/tyk,mvdan/tyk