update webui to 2.1.0

This brings us on-par with js-ipfs.

License: MIT
Signed-off-by: Steven Allen <steven@stebalien.com>

core/corehttp/webui.go

 package corehttp
 
 // TODO: move to IPNS
-const WebUIPath = "/ipfs/QmRuvWJz1Fc8B9cTsAYANHTXqGmKR9DVfY5nvMD1uA2WQ8"
+const WebUIPath = "/ipfs/QmSDgpiHco5yXdyVTfhKxr3aiJ82ynz8V14QcGKicM3rVh"
 
 // this is a list of all past webUI paths.
 var WebUIPaths = []string{
 	WebUIPath,
+	"/ipfs/QmRuvWJz1Fc8B9cTsAYANHTXqGmKR9DVfY5nvMD1uA2WQ8",
 	"/ipfs/QmQLXHs7K98JNQdWrBB2cQLJahPhmupbDjRuH1b9ibmwVa",
 	"/ipfs/QmXX7YRpU7nNBKfw75VG7Y1c3GwpSAGHRev67XVPgZFv9R",
 	"/ipfs/QmXdu7HWdV6CUaUabd9q2ZeA4iHZLVyDRj3Gi4dsJsWjbr",