nodes/{htz.ex42-1048908,htz-cloud.pirmasens}: make sure we have redis installed

nodes/htz-cloud/pirmasens.py

@@ -20,6 +20,11 @@ nodes['htz-cloud.pirmasens'] = {
                 'gateway6': 'fe80::1',
             },
         },
+        'apt': {
+            'packages': {
+                'redis': {},
+            },
+        },
         'cron': {
             'backup': '0 2 * * *    root    /root/backup.sh',
         },

nodes/htz/ex42-1048908.py

@@ -36,6 +36,7 @@ nodes['htz.ex42-1048908'] = {
         'apt': {
             'packages': {
                 'php-imagick': {},
+                'redis': {},
 
                 # No need to create a bundle just to install packages,
                 # configs will be managed by users nevertheless. Maybe