增加不能创建admin用户的校验

core-api/src/main/java/cn/com/qmth/examcloud/service/core/service/UserService.java

@@ -304,12 +304,14 @@ public class UserService {
 		return userRepo.save(user);
 	}
 
-	private void checkLoginName(Long rootOrgId,String loginName) {
-		User old = userRepo.findByRootOrgIdAndLoginName(rootOrgId,loginName);
-		if(old!=null){
-			throw new RuntimeException("用户名已存在");
-		}
-	}
+    private void checkLoginName(Long rootOrgId,String loginName) {
+        User old = userRepo.findByRootOrgIdAndLoginName(rootOrgId,loginName);
+        if(old!=null){
+            throw new RuntimeException("用户名已存在");
+        }else if("admin".equalsIgnoreCase(loginName)){
+            throw new RuntimeException("不能创建admin用户");
+        }
+    }
 
 	public User update(Long id, User user) {
 		User old =  userRepo.findOne(id);