修复 本地不存在的会话收到 1 条消息，角标会+2 的问题

sdk/init/msgEvent.js

@@ -61,7 +61,12 @@ msgEvent.onMsg(async res=>{
     } = msg
     // console.log('msgmsgmsgmsgmsg.msg',msg);
     // 拿到收到消息的会话对象
-    let conversation = await $state.conversation.get(conversation_id)
+    let conversation = $state.conversation.getCached(conversation_id)
+    let isNewCreateConversation = false
+    if (!conversation) {
+      isNewCreateConversation = true
+      conversation = await $state.conversation.get(conversation_id)
+    }
     
     // 处理其他设备已读某会话的情况
     if (msg.type == 'clear-conversation-unreadCount') {
@@ -126,7 +131,9 @@ msgEvent.onMsg(async res=>{
         isReadableMsg &&
         // 消息不是系统配置了免打扰的
         !isMuteMsg &&
-        msg.from_uid != uniCloud.getCurrentUserInfo().uid
+        msg.from_uid != uniCloud.getCurrentUserInfo().uid &&
+        // 新创建的会话直接读取云端的未读消息数，本地不需要 ++
+        !isNewCreateConversation
       ) {
         conversation.unread_count++
       }