patch 4.1 bug fix and remove some secret url

src/sql/engine/expr/ob_expr_char.cpp

@@ -68,7 +68,6 @@ int ObExprChar::calc_result_typeN(ObExprResType &type, ObExprResType *types, int
   } else {
     //set calc type
     //i starts from 1 rather than 0 since the first param is obvarchar always.
-    //see http://review.alibaba-inc.com/r/21109/ for more details when necessary.
     for (int64_t i = 0; i < param_num-1; ++i) {
       types[i].set_calc_type(ObIntType);
     }

src/sql/engine/expr/ob_expr_orahash.cpp

@@ -66,7 +66,7 @@ int ObExprOrahash::calc_result_typeN(ObExprResType &type,
   return ret;
 }
 
-//算法详见 https://yuque.antfin-inc.com/ob-public/sql/sfaedg
+//算法详见
 uint64_t ObExprOrahash::hash_mod_oracle(uint64_t val, uint64_t buckets) const
 {
   uint64_t N = 1;