Fix event ordering issue.
Fix event ordering issue.

Because of how Boost signals is used at present, PutManifest can come
before InstallationComplete.

advancedtelematic/aktualizr,advancedtelematic/sota_client_cpp,advancedtelematic/sota_client_cpp,advancedtelematic/aktualizr,advancedtelematic/aktualizr,advancedtelematic/aktualizr