#73 restore authentication

src/main/java/ru/ulstu/user/util/UserUtils.java

@@ -23,9 +23,6 @@ public class UserUtils {
         }
         final Authentication authentication = securityContext.getAuthentication();
 
-        if (authentication == null) {
-            return "admin";
-        }
         if (authentication.getPrincipal() instanceof UserDetails) {
             final UserDetails springSecurityUser = (UserDetails) authentication.getPrincipal();
             return springSecurityUser.getUsername();