FIX: checksum task

tasks/loki_install.yml

@@ -37,7 +37,7 @@
     url: "{{ loki_dist_url }}"
     dest: "{{ loki_dist_location }}"
     tmp_dest: "/tmp/"
-    checksum: "{{ loki_checksum }}"
+    checksum: "sha256:{{ loki_checksum }}"
   become: yes
   become_user: "{{ loki_user }}"