[][MAC80211][hostapd][Fix uci set invalid bss color]

[Description]
Fix uci set invalid bss color cause bring up interface failed.

[Release-log]
N/A

Change-Id: I576df3e4e566f6ab630e59cbaf97c7af11fab941
Reviewed-on: https://gerrit.mediatek.inc/c/openwrt/feeds/mtk_openwrt_feeds/+/7510916
1 file changed