daily_tasks.sh: redirect stderr to stdout (#1768)

When the management commands fail, they can print something to the standard error output.
The administrator would never notice, because it wouldn't be send to him with the usual emails.
Fixes #1763

management/daily_tasks.sh

@@ -16,10 +16,10 @@ if [ `date "+%u"` -eq 1 ]; then
 fi
 
 # Take a backup.
-management/backup.py | management/email_administrator.py "Backup Status"
+management/backup.py 2>&1 | management/email_administrator.py "Backup Status"
 
 # Provision any new certificates for new domains or domains with expiring certificates.
-management/ssl_certificates.py -q | management/email_administrator.py "TLS Certificate Provisioning Result"
+management/ssl_certificates.py -q  2>&1 | management/email_administrator.py "TLS Certificate Provisioning Result"
 
 # Run status checks and email the administrator if anything changed.
-management/status_checks.py --show-changes | management/email_administrator.py "Status Checks Change Notice"
+management/status_checks.py --show-changes  2>&1 | management/email_administrator.py "Status Checks Change Notice"