Exception on execution may be lost

In class AbstrSyncDockerCmdExec there is a finally block which throws an exception. This could hide an exception which is thrown in the try block, in case the close statement throws an error.

```
    } finally {
        try {
            command.close();
        } catch (IOException e) {
            throw new RuntimeException(e);
        }
    }
```

The original exception must not lost
