Switch -EN - do not add "end of archive" block

Not supported for RAR 5.0 archives.

By default, WinRAR adds an "end of archive" block to the end of a new or updated archive. It allows to skip external data like digital signatures safely, but in some special cases it may be useful to disable this feature. For example, if an archive is transferred between two systems via an unreliable link and at the same time a sender adds new files to it, it may be important to be sure that the already received file part will not be modified on the other end between transfer sessions.

This switch cannot be used with volumes, because the end of archive block contains information important for correct volume processing.