solr as a system user.

tasks/main.yml

@@ -1,7 +1,7 @@
 ---
 - block:
     - name: Create a solr user
-      user: name={{ solr_user }} home={{ solr_base_dir }} createhome=yes shell=/bin/bash
+      user: name={{ solr_user }} home={{ solr_base_dir }} createhome=yes shell=/bin/bash system=yes
 
     - name: Create the downloads directory
       file: dest={{ solr_download_dir }} state=directory