[FS#805] WNDR4700 - latest r4190 from r4188 - upgrade not working

[LEDE Bugs]

The following task has a new comment added:

FS#805 - WNDR4700 - latest r4190 from r4188 - upgrade not working
User who did this - build000 (build000)

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Update info:
When use "sysupgrade -n" again -> another messages:
root at LEDE:/tmp# sysupgrade -n lede-apm821xx-nand-WNDR4700-squashfs-sysupgrade.tar
Image metadata not found
killall: watchdog: no process killed
Command failed: Request timed out

...and any other action from system/hardware - no flashing/reboot.
This time using new r4208-4b8a7c9.
Size firmware is to not very big - only 13,5 MB (13527040 B) from ~25 MB insted from all size flash.
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More information can be found at the following URL:
https://bugs.lede-project.org/index.php?do=details&task_id=805#comment2670