Define bash as a parser, some systems can have "dash" as a "sh" that will end with errors.
# /usr/local/ispconfig/server/cron_daily.sh
[: 10: root: unexpected operator
[: 10: root: unexpected operator

- backported patches

fixes also some misconfiguration under some circonstances

ensure the internal PHP scripts work even if system-wide PHP settings are set that could affect how ISPConfig would work. See FS#3293