Fix an error in executorservo.py

```
TypeError: make_hosts_file() takes exactly 2 arguments (0 given)
```

tests/wpt/metadata/css/CSS2/floats/intrinsic-size-float-and-line.html.ini

@@ -0,0 +1,2 @@
+[intrinsic-size-float-and-line.html]
+  expected: FAIL

tests/wpt/metadata/css/CSS2/visudet/content-height-005.html.ini

@@ -0,0 +1,2 @@
+[content-height-005.html]
+  expected: FAIL

tests/wpt/metadata/css/css-backgrounds/background-attachment-local/attachment-local-clipping-color-4.html.ini

@@ -1,3 +1,3 @@
 [attachment-local-clipping-color-4.html]
   type: reftest
-  expected: TIMEOUT
+  expected: FAIL

tests/wpt/metadata/css/css-fonts/font-variant-05.xht.ini

@@ -0,0 +1,2 @@
+[font-variant-05.xht]
+  expected: FAIL

tests/wpt/metadata/css/css-fonts/font-variant-06.xht.ini

@@ -0,0 +1,2 @@
+[font-variant-06.xht]
+  expected: FAIL

tests/wpt/metadata/css/mediaqueries/viewport-script-dynamic.html.ini

@@ -0,0 +1,2 @@
+[viewport-script-dynamic.html]
+  expected: FAIL

tests/wpt/metadata/fetch/corb/img-html-correctly-labeled.sub.html.ini

@@ -0,0 +1,2 @@
+[img-html-correctly-labeled.sub.html]
+  expected: FAIL

tests/wpt/metadata/html/dom/dynamic-markup-insertion/opening-the-input-stream/010.html.ini

@@ -0,0 +1,4 @@
+[010.html]
+  [Salvagability of document.opened document]
+    expected: FAIL
+

tests/wpt/web-platform-tests/tools/wptrunner/wptrunner/executors/executorservo.py

@@ -185,7 +185,7 @@ class ServoRefTestExecutor(ProcessTestExecutor):
         self.screenshot_cache = screenshot_cache
         self.implementation = RefTestImplementation(self)
         self.tempdir = tempfile.mkdtemp()
-        self.hosts_path = make_hosts_file()
+        self.hosts_path = write_hosts_file(server_config)
 
     def teardown(self):
         try: