[TASK] Improve deprecation message in show_rechis.php

Use a more detailed message how to link to this script.

Resolves: #61458
Releases: 6.3, 6.2
Change-Id: Ifabac9033b72bea288b13a11d1e649f28b99f950
Reviewed-on: http://review.typo3.org/32659
Reviewed-by: Christian Kuhn <lolli@schwarzbu.ch>
Tested-by: Christian Kuhn <lolli@schwarzbu.ch>