use more variables instead of hard-coding (fixes #3)

tasks/borgbackup-Debian.yml

@@ -1,8 +1,9 @@
 ---
 # Server/Borgbackup: Install and Setup Borgbackup Backup Crobjob - Default Debian Version
 # Variables (must be set!):
-# - borgbackup_host
-# - borgbackup_sub
+# - borgbackup_passhrase
+# - borgbackup_repo
+# - borgbackup_hostname
 
 # For all other Debian versions, simply install borgbackup
 
@@ -12,6 +13,7 @@
     name: borgbackup
     state: present
   when:
-    - borgbackup_host is defined
-    - borgbackup_sub is defined
+    - borgbackup_passphrase is defined
+    - borgbackup_repo is defined
+    - borgbackup_hostname is defined
     - ansible_distribution_release != 'stretch'