Remove unnecessary generic type arguments

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Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=175155365

javatests/google/registry/util/TeeOutputStreamTest.java

@@ -61,7 +61,7 @@ public class TeeOutputStreamTest {
   @SuppressWarnings("resource")
   public void testConstructor_failsWithEmptyIterable() {
     thrown.expect(IllegalArgumentException.class);
-    new TeeOutputStream(ImmutableSet.<OutputStream>of());
+    new TeeOutputStream(ImmutableSet.of());
   }
 
   @Test