fix(browser): add null check for crawlerRunConfig.url

Add additional null check when accessing crawlerRunConfig.url in cookie configuration to prevent potential null pointer exceptions. Previously, the code only checked if crawlerRunConfig existed but not its url property.

Fixes potential runtime error when crawlerRunConfig.url is undefined.

crawl4ai/browser_manager.py

@@ -658,7 +658,7 @@ class BrowserManager:
                     "name": "cookiesEnabled",
                     "value": "true",
                     "url": crawlerRunConfig.url
-                    if crawlerRunConfig
+                    if crawlerRunConfig and crawlerRunConfig.url
                     else "https://crawl4ai.com/",
                 }
             ]