make sure ImageMagick is installed and configured for PDFs

roles/calibre-web/tasks/main.yml

@@ -1,3 +1,18 @@
+- name: Install ImageMagick (debuntu)
+  package:
+    name:
+      - imagemagick
+    state: present
+  when: is_debuntu
+
+- name: Allow ImageMagick to read PDFs
+  lineinfile:
+    path: /etc/ImageMagick-6/policy.xml
+    regexp: '^<policy domain="coder" rights="none" pattern="PDF" />'
+    line: '<policy domain="coder" rights="read" pattern="PDF" />'
+    state: present
+  when: is_debuntu
+
 - name: Create 3 Calibre-Web folders to store data and configuration files
   file:
     path: "{{ item }}"