MDEV-12071 storage/xtradb/handler/ha_innodb.cc: Cannot assign const_iterator to iterator

Author: dr-m

storage/xtradb/handler/ha_innodb.cc

@@ -13339,7 +13339,8 @@ fill_foreign_key_list(THD* thd,
 {
 ut_ad(mutex_own(&dict_sys->mutex));
 
-for (dict_foreign_set::iterator it = table->referenced_set.begin();
+for (dict_foreign_set::const_iterator it
+ = table->referenced_set.begin();
  it != table->referenced_set.end(); ++it) {
 
 dict_foreign_t* foreign = *it;