update onlyoffice detection to support sheet migration

docs/example.nginx.conf

@@ -103,7 +103,7 @@ server {
     # they unfortunately still require exceptions to the sandboxing to work correctly.
     if ($uri = "/pad/inner.html") { set $unsafe 1; }
     if ($uri = "/sheet/inner.html") { set $unsafe 1; }
-    if ($uri = "/common/onlyoffice/web-apps/apps/spreadsheeteditor/main/index.html") { set $unsafe 1; }
+    if ($uri ~ ^\/common\/onlyoffice\/.*\/index\.html.*$) { set $unsafe 1; }
 
     # everything except the sandbox domain is a privileged scope, as they might be used to handle keys
     if ($host != sandbox.cryptpad.info) { set $unsafe 0; }