Clone credentials when passing to node

Fixes #1198

red/runtime/nodes/index.js

@@ -17,6 +17,7 @@
 var when = require("when");
 var path = require("path");
 var fs = require("fs");
+var clone = require("clone");
 
 var registry = require("./registry");
 var credentials = require("./credentials");
@@ -69,6 +70,7 @@ function createNode(node,def) {
     }
     var creds = credentials.get(id);
     if (creds) {
+        creds = clone(creds);
         //console.log("Attaching credentials to ",node.id);
         // allow $(foo) syntax to substitute env variables for credentials also...
         for (var p in creds) {