Merge pull request #4226 from breez/fix-chainrpc-crash

Fix crash when ChainNotifier is being accessed too early.

sweep/test_utils.go

@@ -200,6 +200,11 @@ func (m *MockNotifier) Start() error {
 	return nil
 }
 
+// Started checks if started
+func (m *MockNotifier) Started() bool {
+	return true
+}
+
 // Stop the notifier.
 func (m *MockNotifier) Stop() error {
 	return nil