Fix href-to persists hash

Copy passed hash before manipulating it.

Assigning to the same hash object will break href-to
because in certain scenarios href-to-helper will
not create a new object that gets passed to
`fsm-with-optional`-hrefTo method.

This is problematic for optional route-params, and lead
to a situation where links to peered services would
create the wrong url for their href-attribute.

ui/packages/consul-ui/app/locations/fsm-with-optional.js

@@ -188,10 +188,14 @@ export default class FSMWithOptionalLocation {
   /**
    * Turns a routeName into a full URL string for anchor hrefs etc.
    */
-  hrefTo(routeName, params, hash) {
+  hrefTo(routeName, params, _hash) {
+    // copy to always work with a new hash even when helper persists hash
+    const hash = { ..._hash };
+
     if (typeof hash.dc !== 'undefined') {
       delete hash.dc;
     }
+
     if (typeof hash.nspace !== 'undefined') {
       hash.nspace = `~${hash.nspace}`;
     }