Minor refactor.

src/util/memUsage.ts

@@ -297,8 +297,8 @@ function ongoingMemoryDump() {
         log.warn("Unexpected error while writing memory stats log", err);
       }
     },
-    60 * 60 * 1000,
-  ); // every 60 minutes
+    15 * 60 * 1000,
+  ); // every 15 minutes
 }
 
 export default ongoingMemoryDump;