Posts/Users pages are blank when user not logged in (#560)

* fix: metadata fails when user not logged in

this additional checks makes sure verification / node.deso.org metadata is only requested if loggedInUserPublicKey is ok. Currently it requests metadata from `https://node.deso.org/api/v0/get-user-metadata/undefined` which returns status 404 error and prevents post/user pages from showing the content.

* align with diamondapp

use same approach as DiamondApp

Author: tijno

src/app/app.component.ts

@@ -114,7 +114,7 @@ export class AppComponent implements OnInit {
 
     return zip(
       this.backendApi.GetUsersStateless(this.globalVars.localNode, [loggedInUserPublicKey], false),
-      environment.verificationEndpointHostname
+      environment.verificationEndpointHostname && !_.isNil(loggedInUserPublicKey)
         ? this.backendApi.GetUserMetadata(environment.verificationEndpointHostname, loggedInUserPublicKey).pipe(
             catchError((err) => {
               console.error(err);