Removed duplicate test.

mysql-test/t/mysqldump.test:
  Removed duplicate test. This is already in the test file.

mysql-test/t/mysqldump.test

@@ -712,15 +712,6 @@ select * from t1;
 
 drop table t1;
 
-#
-# Bug #13318: Bad result with empty field and --hex-blob
-# 
-create table t1 (a binary(1), b blob);
-insert into t1 values ('','');
---exec $MYSQL_DUMP --skip-comments --skip-extended-insert --hex-blob test t1
---exec $MYSQL_DUMP --skip-comments --hex-blob test t1
-drop table t1;
-
 #
 # BUG #19025 mysqldump doesn't correctly dump "auto_increment = [int]"
 #