Fix blank page when loading a changeset while not logged in (#796)

Author: jake-low

src/views/map.js

@@ -110,7 +110,7 @@ class CMap extends React.PureComponent {
   }
 
   initializeMap() {
-    if (!this.props.changeset) {
+    if (!this.props.token || !this.props.changeset) {
       return;
     }