ui/ux: fix username appearance

This patch displays ringID if username is empty string

Change-Id: Ib1c7f261e5242f55783f3d462e75eef73e89e7ec
Reviewed-by: Andreas Traczyk <andreas.traczyk@savoirfairelinux.com>

Ring/Ring/Features/ContactRequests/ContactRequestsViewModel.swift

@@ -95,7 +95,7 @@ class ContactRequestsViewModel: ViewModel {
                 return lookupNameResponse.address == item.contactRequest.ringId
             })
             .subscribe(onNext: { lookupNameResponse in
-                if lookupNameResponse.state == .found {
+                if lookupNameResponse.state == .found && !lookupNameResponse.name.isEmpty {
                     item.userName.value = lookupNameResponse.name
                 } else {
                     item.userName.value = lookupNameResponse.address

Ring/Ring/Features/Conversations/Conversation/ConversationViewModel.swift

@@ -103,7 +103,7 @@ class ConversationViewModel: ViewModel {
                         return lookupNameResponse.address != nil &&
                             lookupNameResponse.address == recipientRingId
                     }).subscribe(onNext: { [unowned self] lookupNameResponse in
-                        if let name = lookupNameResponse.name {
+                        if let name = lookupNameResponse.name, !name.isEmpty {
                             self.userName.onNext(name)
                             contact?.userName = name
                         } else if let address = lookupNameResponse.address {