add file header

bubble-server/src/main/java/bubble/service_dbfilter/DbFilterAuthenticatorService.java

@@ -1,3 +1,7 @@
+/**
+ * Copyright (c) 2020 Bubble, Inc.  All rights reserved.
+ * For personal (non-commercial) use, see license: https://bubblev.com/bubble-license/
+ */
 package bubble.service_dbfilter;
 
 import bubble.model.account.Account;