Bug Fix: #4366 Creating Index doesn't update index-list.

Bug Fix: #4366 Creating Index doesn't update index-list.
http://sourceforge.net/p/phpmyadmin/bugs/4366/

This commit fixes the following bugs:
- Bug #4366 itself.
- Index list is gone on dropping a column from tbl_structure page.

Signed-off-by: Ashutosh Dhundhara <ashutoshdhundhara@yahoo.com>