MDEV-25273: fix typo (s/strucures/structures/)

Author: chansuke

sql/share/errmsg-utf8.txt

@@ -7637,7 +7637,7 @@ ER_JSON_SYNTAX
 ER_JSON_ESCAPING
         eng "Incorrect escaping in JSON text in argument %d to function '%s' at position %d"
 ER_JSON_DEPTH
-        eng "Limit of %d on JSON nested strucures depth is reached in argument %d to function '%s' at position %d"
+        eng "Limit of %d on JSON nested structures depth is reached in argument %d to function '%s' at position %d"
 ER_JSON_PATH_EOS
         eng "Unexpected end of JSON path in argument %d to function '%s'"
 ER_JSON_PATH_SYNTAX