Delete cache from all hosts on a WP standard installation.

See wpsharks/comet-cache#608

src/includes/traits/Shared/CacheDirUtils.php

@@ -269,6 +269,18 @@ public function deleteFilesFromHostCacheDir(
         if (!is_dir($cache_dir = $this->cacheDir())) {
             return $counter; // Nothing to do.
         }
+        // On a standard installation delete from all hosts.
+        // See: <https://github.com/websharks/comet-cache/issues/608>
+        if (!is_multisite() && !$___considering_domain_mapping) {
+            $regex = ltrim($regex, '^\\/');
+
+            if (mb_strpos($regex, '(?:\/') === 0 || mb_strpos($regex, '(\/') === 0) {
+                $regex = '/^https?\/[^\/]+'.$regex;
+            } else {
+                $regex = '/^https?\/[^\/]+\/'.$regex;
+            }
+            return $this->deleteFilesFromCacheDir($regex, $check_max_age);
+        }
         $cache_dir            = $this->nDirSeps($cache_dir); // Normalize.
         $host_token           = $current_host_token           = $this->hostToken();
         $host_base_dir_tokens = $current_host_base_dir_tokens = $this->hostBaseDirTokens();