[FS#1312] opkg update is not using SSL

[LEDE Bugs]

The following task is now closed:

FS#1312 - opkg update is not using SSL
User who did this - Yousong Zhou (yousong)

Reason for closing: Won't fix
Additional comments about closing: mitm attack won't work because it has signature check.

More information can be found at the following URL:
https://bugs.lede-project.org/index.php?do=details&task_id=1312