[FS#1486] `ping` from `iputils-ping` is not respecting the `-I` option

[LEDE Bugs]

A new Flyspray task has been opened.  Details are below. 

User who did this - Tian Yunhao (t123yh) 

Attached to Project - OpenWrt/LEDE Project
Summary - `ping` from `iputils-ping` is not respecting the `-I` option
Task Type - Bug Report
Category - Packages
Status - Unconfirmed
Assigned To - 
Operating System - All
Severity - Low
Priority - Very Low
Reported Version - Trunk
Due in Version - Undecided
Due Date - Undecided
Details - There're two WAN connections in my router. I installed `iputils-ping` for some fancy features. If I use `ping -I wan2 x.x.x.x`, the ICMP Echo request will still be sent from the main wan interface, ignoring the `-I` option. Busybox ping doesn't have this problem. 

The iputils-* packages are version 20101006. This issue is solved by [[https://github.com/iputils/iputils/commit/f455fee41c077d4b700a473b2f5b3487b8febc1d|this commit]] and I suggest that the iputils packages should be updated.

More information can be found at the following URL:
https://bugs.openwrt.org/index.php?do=details&task_id=1486