fix: restore proxy functionality for PlaywrightCrawler broken in v0.5 (#889)

### Description

- fix for proxy in PlaywrightCrawler 

### Issues

- Closes: #887

### Testing

- Added test to verify proxy is correctly set for PlaywrightCrawler

Author: Mantisus

src/crawlee/browsers/_playwright_browser_controller.py

@@ -171,7 +171,7 @@ async def _create_browser_context(
         )
 
         if proxy_info:
-            if browser_new_context_options['proxy']:
+            if browser_new_context_options.get('proxy'):
                 logger.warning("browser_new_context_options['proxy'] overriden by explicit `proxy_info` argument.")
 
             browser_new_context_options['proxy'] = ProxySettings(

tests/unit/crawlers/_playwright/test_playwright_crawler.py

@@ -18,11 +18,12 @@
     PW_CHROMIUM_HEADLESS_DEFAULT_USER_AGENT,
     PW_FIREFOX_HEADLESS_DEFAULT_USER_AGENT,
 )
+from crawlee.proxy_configuration import ProxyConfiguration
 
 if TYPE_CHECKING:
     from yarl import URL
 
-    from crawlee.crawlers import PlaywrightCrawlingContext
+    from crawlee.crawlers import PlaywrightCrawlingContext, PlaywrightPreNavCrawlingContext
 
 
 async def test_basic_request(httpbin: URL) -> None:
@@ -188,3 +189,28 @@ async def request_handler(_context: PlaywrightCrawlingContext) -> None:
     await crawler.run(['https://example.com', str(httpbin)])
 
     assert mock_hook.call_count == 2
+
+
+async def test_proxy_set() -> None:
+    # Configure crawler with proxy settings
+    proxy_value = 'http://1111:1111'
+    crawler = PlaywrightCrawler(proxy_configuration=ProxyConfiguration(proxy_urls=[proxy_value]))
+
+    handler_data = {}
+
+    mock_handler = mock.AsyncMock(return_value=None)
+    crawler.router.default_handler(mock_handler)
+
+    # Use pre_navigation_hook to verify proxy and configure playwright route
+    @crawler.pre_navigation_hook
+    async def some_hook(context: PlaywrightPreNavCrawlingContext) -> None:
+        if context.proxy_info:
+            # Store information about the used proxy
+            handler_data['proxy'] = context.proxy_info.url
+
+        # Emulate server response to prevent Playwright from making real requests
+        await context.page.route('**/*', lambda route: route.fulfill(status=200))
+
+    await crawler.run(['https://test.com'])
+
+    assert handler_data.get('proxy') == proxy_value