[Core] fix group image send (#106)

Author: Redmomn

Lagrange.Core/Internal/Packets/Service/NTV2RichMedia.cs

@@ -47,7 +47,7 @@ public static NTV2RichMediaReq BuildUploadReq(
                 TryFastUploadCompleted = true,
                 SrvSendMsg = false,
                 ClientRandomId = (ulong)Random.Shared.Next(),
-                CompatQMsgSceneType = 1,
+                CompatQMsgSceneType = @struct.IsGroup()? 2u : 1u ,
                 ClientSeq = 10,
                 ExtBizInfo = ext,
                 NoNeedCompatMsg = false