Pin Selfoss version to an actual release

roles/news/tasks/selfoss.yml

   git: repo=https://github.com/SSilence/selfoss.git
        dest=/var/www/selfoss
        accept_hostkey=yes
-       version=master
+       version={{ selfoss_version }}
 
 - name: Set selfoss ownership
   action: file owner=root group=www-data path=/var/www/selfoss recurse=yes state=directory

vars/defaults.yml

 selfoss_db_username: selfoss
 # selfoss_db_password: (required)
 selfoss_db_database: selfoss
+selfoss_version: 2.14
 
 # git
 cgit_version: 0.10.1