Updates permissions on 97-mysql-iptables

File permissions were -rw-rw-r--.
Permissions need to be  +x to be run by os-refresh-config.
Updated 97-mysql-iptables file permissions to match the other iptables files.

Change-Id: I9a3e041031c08928c7a7cf9cd24ebf0c856f3ece
Merge "Updates permissions on 97-mysql-iptables"