add test for gallery previous installation

roles/gallery/tasks/main.yml

@@ -23,6 +23,18 @@
     web_user: lighttpd
     web_group: lighttpd
     proxy_port: 3031
+  block:
+    - name: test if gallery is already installed
+      find:
+        paths: "{{ folder }}"
+        pattern: README
+      register: check_installed
+
+    - set_fact:
+        install_gallery: "{{ check_installed.matched == 0 }}"
+
+    - name: install block
+      when: install_gallery
       block:
       - name: add mod_scgi.conf include to lighttpd.conf
         lineinfile: