Eliminate some elastic search dependency

src/main/java/at/ac/uibk/gitsearch/service/UserService.java

@@ -9,7 +9,6 @@ import at.ac.uibk.gitsearch.security.AuthoritiesConstants;
 import at.ac.uibk.gitsearch.security.SecurityUtils;
 import at.ac.uibk.gitsearch.service.dto.AdminUserDTO;
 import at.ac.uibk.gitsearch.service.dto.UserDTO;
-
 import java.time.Instant;
 import java.time.temporal.ChronoUnit;
 import java.util.HashSet;
@@ -19,7 +18,6 @@ import java.util.Objects;
 import java.util.Optional;
 import java.util.Set;
 import java.util.stream.Collectors;
-
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 import org.springframework.cache.CacheManager;
@@ -30,7 +28,6 @@ import org.springframework.security.core.authority.SimpleGrantedAuthority;
 import org.springframework.security.crypto.password.PasswordEncoder;
 import org.springframework.stereotype.Service;
 import org.springframework.transaction.annotation.Transactional;
-
 import tech.jhipster.security.RandomUtil;
 
 /**