Yang Classic: fix timestamp

opponents/yang/meta.xml

 <?xml version='1.0' encoding='UTF-8'?>
 <opponent>
-    <lastupdate>1629995452148</lastupdate>
+    <lastupdate>1548093960000</lastupdate>
     <enabled>true</enabled>
     <first>Yang</first>
     <last>Xiao Long</last>