More appropriate error message

Project files can't be a directory.

Contributes to issue CURA-7996.

cura/CuraApplication.py

@@ -1947,7 +1947,7 @@ class CuraApplication(QtApplication):
             return result == WorkspaceReader.PreReadResult.accepted
         except FileNotFoundError:
             result_message = Message(text = self._i18n_catalog.i18nc("@info:status Don't translate the XML tag <filename>!",
-                                                                     "Failed to load <filename>{0}</filename>. No such file or directory.",
+                                                                     "Failed to load <filename>{0}</filename>. File is moved or deleted.",
                                                                      file_path), lifetime = 0,
                                      title = self._i18n_catalog.i18nc("@info:title", "Unable to Open File"))
             result_message.show()