Remove unused org.mockito.Spy import

Author: Surya Srinivasan

server/src/test/java/com/cloud/user/AccountManagerImplTest.java

@@ -57,7 +57,6 @@
 import org.mockito.Mockito;
 import org.mockito.junit.MockitoJUnitRunner;
 import org.mockito.InjectMocks;
-import org.mockito.Spy;
 import org.springframework.beans.factory.NoSuchBeanDefinitionException;