Initialize MockWebServer in setUp() not construction time

Should be a no-op but makes test suite creation cheaper.

Bug: 29820565
Change-Id: I481e2cf3864bb3632779b41e80e0c1032f897ee2
diff --git a/src/test/java/com/google/mockwebserver/MockWebServerTest.java b/src/test/java/com/google/mockwebserver/MockWebServerTest.java
index a8d5331..64c0f68 100644
--- a/src/test/java/com/google/mockwebserver/MockWebServerTest.java
+++ b/src/test/java/com/google/mockwebserver/MockWebServerTest.java
@@ -32,7 +32,13 @@
 
 public final class MockWebServerTest extends TestCase {
 
-    private MockWebServer server = new MockWebServer();
+    private MockWebServer server;
+
+    @Override
+    public void setUp() throws Exception {
+        super.setUp();
+        server = new MockWebServer();
+    }
 
     @Override protected void tearDown() throws Exception {
         server.shutdown();