test: fix call from service to facade

src/test/java/cz/muni/fi/pa165/icehockeymanager/facades/TeamManagerFacadeImplTest.java

@@ -52,7 +52,7 @@ public class TeamManagerFacadeImplTest {
     @Test
     public void getFreePlayersEmpty() {
         when(playerService.getFreePlayers()).thenReturn(new ArrayList<>());
-        assertThat(playerService.getFreePlayers()).isEmpty();
+        assertThat(teamManagerFacade.getFreePlayers()).isEmpty();
         verify(playerService).getFreePlayers();
     }