Replace deprecated Truth hasMessage() method with hasMessageThat()

hasMessageThat() was added in Truth 0.32 and we are already on that
version in the Nomulus release.

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Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=153095111

javatests/google/registry/tools/CreateReservedListCommandTest.java

@@ -175,7 +175,7 @@ public class CreateReservedListCommandTest extends
       assertWithMessage("Expected IllegalArgumentException to be thrown").fail();
     } catch (IllegalArgumentException e) {
       assertThat(ReservedList.get(name)).isAbsent();
-      assertThat(e).hasMessage(expectedErrorMsg);
+      assertThat(e).hasMessageThat().isEqualTo(expectedErrorMsg);
     }
   }