修复NPE

core/src/main/java/com/wecloud/im/service/impl/ImMessageServiceImpl.java

@@ -675,7 +675,8 @@ public class ImMessageServiceImpl extends BaseServiceImpl<ImMessageMapper, ImMes
         String toUserIdsStr = param.getToUserIds();
         List<String> toUserIdList = Arrays.asList(toUserIdsStr.split(","));
         // 获取发件人信息
-        ImClient sender = imClientService.getCacheImClient(appId, senderClientId);
+        ImClient sender =
+                imClientService.getOne(Wrappers.<ImClient>lambdaQuery().eq(ImClient::getFkAppid, appId).eq(ImClient::getClientId, senderClientId));
         if (sender == null) {
             throw new BusinessException("id为 " + senderClientId + " 的发件人不存在");
         }
@@ -822,6 +823,7 @@ public class ImMessageServiceImpl extends BaseServiceImpl<ImMessageMapper, ImMes
             conversationCreate.setCreator(sender);
             conversationCreate.setMembers(members);
             conversationCreate.setChatType(ChatTypeEnum.SINGLE);
+            conversationCreate.setApplication(application);
             ImConversation conversation = imConversationService.serverCreateImConversation(conversationCreate);
             // 构建ImConversationMembers(只保存必要信息)
             ImConversationMembers receiverMember = new ImConversationMembers();