avoid wildcard imports

Author: Vladimir Kotal

opengrok-web/src/test/java/org/opengrok/web/DirectoryListingTest.java

@@ -53,7 +53,11 @@
 import static org.junit.Assert.assertTrue;
 import static org.junit.Assert.fail;
 import static org.mockito.ArgumentMatchers.anyString;
-import static org.mockito.Mockito.*;
+import static org.mockito.Mockito.atLeast;
+import static org.mockito.Mockito.mock;
+import static org.mockito.Mockito.when;
+import static org.mockito.Mockito.spy;
+import static org.mockito.Mockito.verify;
 
 /**
  * JUnit test to test that the DirectoryListing produce the expected result.