pfSense

Upgrading an old config that has set but empty gateway interval tags throws a php error.
For example a config containing:

        <gateway_item>
            <interface>wan</interface>
            <gateway>1.2.3.4</gateway>
            <name>wan_gateway</name>
            <weight/>
            <interval/>
            <descr><![CDATA[gw1]]></descr>
            <defaultgw/>
        </gateway_item>

Will hit:

Fatal error: Uncaught TypeError: Unsupported operand types: string * int in /etc/inc/upgrade_config.inc:4169
Stack trace:
#0 /etc/inc/config.lib.inc(519): upgrade_130_to_131()
#1 /etc/rc.bootup(140): convert_config()
#2 {main}
 thrown in /etc/inc/upgrade_config.inc on line 4169
PHP ERROR: Type: 1, File: /etc/inc/upgrade_config.inc, Line: 4169, Message: Uncaught TypeError: Unsupported operand types: string * int in /etc/inc/upgrade_config.inc:4169
Stack trace:
#0 /etc/inc/config.lib.inc(519): upgrade_130_to_131()
#1 /etc/rc.bootup(140): convert_config()
#2 {main}