FIX: 'resource request errors' close the server.

The test "should handle resource request errors"
was not closing the server at the end of the test,
interfering with the successive tests.

test/webpage-spec.js

@@ -1078,6 +1078,7 @@ describe("WebPage object", function() {
         
         runs(function() {
             expect(handled).toEqual(true);
+            server.close();
         });
     });