Update signal config.yaml.j2 merging upstream changes

roles/custom/matrix-bridge-mautrix-signal/templates/config.yaml.j2

@@ -101,7 +101,7 @@ bridge:
     # {{.UUID}} - The UUID of the Signal user.
     # {{.AboutEmoji}} - The emoji set by the user in their profile.
     # {% endraw %}
-    displayname_template: "{{ '{{.ProfileName}} (Signal)' }}"
+    displayname_template: "{{ 'or .ProfileName .PhoneNumber "Unknown user" (Signal)' }}"
     # Whether to explicitly set the avatar and room name for private chat portal rooms.
     # If set to `default`, this will be enabled in encrypted rooms and disabled in unencrypted rooms.
     # If set to `always`, all DM rooms will have explicit names and avatars set.