A post fix for BUG#45645 Mysql server close all connection and restart using lower function

- Initialized caseinfo only if it is NULL

strings/ctype-uca.c

@@ -7858,7 +7858,8 @@ static my_bool create_tailoring(CHARSET_INFO *cs, void *(*alloc)(size_t))
     return 1;
   }
   
-  cs->caseinfo= my_unicase_default;
+  if (!cs->caseinfo)
+    cs->caseinfo= my_unicase_default;
   
   if (!(newweights= (uint16**) (*alloc)(256*sizeof(uint16*))))
     return 1;