added username for uniqueness of connection db entry

backend/src/main/java/com/vaessl/app/connection/HomeBoxConnectionProvider.java

@@ -54,6 +54,12 @@ public class HomeBoxConnectionProvider implements ConnectionProvider {
         return new ConnectionResponse(hbResponse.token(), hbResponse.expiresAt(), attachmentToken);
     }
 
+    @Override
+    public ConnectionEntity findUniqueConnectionEntry(ConnectionRequest request) {
+
+        return cRepository.findByAppUrlAndUsername(request.appUrl(), request.credentials().get("username"));
+    }
+
     @Override
     public ConnectionEntity connectionToEntity(ConnectionRequest request, ConnectionResponse response) {
         return HomeboxEntity.from(request, response);