fix: self leave group is treated as QUIT instead of UPDATE

app/src/main/java/org/thoughtcrime/securesms/loki/protocol/ClosedGroupsProtocolV2.kt

@@ -638,7 +638,7 @@ object ClosedGroupsProtocolV2 {
         }
         if (userPublicKey == senderPublicKey) {
             val threadID = DatabaseFactory.getLokiThreadDatabase(context).getThreadID(groupID)
-            insertOutgoingInfoMessage(context, groupID, GroupContext.Type.UPDATE, name, members, admins, threadID, sentTimestamp)
+            insertOutgoingInfoMessage(context, groupID, GroupContext.Type.QUIT, name, members, admins, threadID, sentTimestamp)
         } else {
             insertIncomingInfoMessage(context, senderPublicKey, groupID, GroupContext.Type.UPDATE, SignalServiceGroup.Type.UPDATE, name, members, admins)
         }