Upgrade mockito in web module

Author: ahornace

opengrok-web/pom.xml

@@ -124,7 +124,7 @@ Portions Copyright (c) 2018, Chris Fraire <[email protected]>.
         <dependency>
             <groupId>org.mockito</groupId>
             <artifactId>mockito-core</artifactId>
-            <version>2.19.0</version>
+            <version>2.28.2</version>
             <scope>test</scope>
         </dependency>
         <dependency>