Revert "Revert "Temporarily disable CSP in Nextcloud.""

This reverts commit cfba896a.

Here we go again.

conf.d/nextcloud.shore.co.il.conf

@@ -27,5 +27,8 @@ server {
         include                 snippets/proxy-headers.conf;
         proxy_hide_header       X-Frame-Options;
         client_max_body_size    512m;
+        # Temporary measure to test a Collabora Online issue, should not be left
+        # as is.
+        proxy_hide_header       content-security-policy;
     }
 }