Revert "Backport of improvements to otrs.SetPermissions.pl: also set permission on OTRS home directory."

This reverts commit 15cb6d562a6cf77a81cb6c46239f8f99e610fc06.
Revert "Backport of improvements to otrs.SetPermissions.pl: also set permission on OTRS home directory."

This reverts commit 4acd1a8c9b7fce64bc22d2f5269bf3783edd9951.
Added .procmailrc to gitignore.
Improved permissions of /opt/otrs.
Tidied code.