drop outdated comment about updating repo

Signed-off-by: Jakub Sokołowski <jakub@status.im>

tasks/build.yml

@@ -5,8 +5,7 @@
     version: '{{ beacon_node_repo_branch }}'
     dest: '{{ beacon_node_repo_path }}'
     force: true
-    # Normally we don't update or timer might miss some changes.
-    # update: '{{ item.get("update", false) }}'
+    update: true
   become_user: '{{ beacon_node_user }}'
 
 - name: Create build script