gluon-status-page: use UCI + iwinfo to get channel information

The network.wireless status ubus call only returns the configured
channel from UCI, breaking the status page in outdoor mode, where the
configuration contains 'auto' instead of a number.

Fixes: 0d3fa6b5 ("gluon-status-page: use ubus to get radio channels")
Closes #2336

package/gluon-status-page/files/lib/gluon/status-page/view/status-page.html

 <%-
+	local iwinfo = require 'iwinfo'
 	local ubus = require 'ubus'
 	local unistd = require 'posix.unistd'
 	local util = require 'gluon.util'
+	local wireless = require 'gluon.wireless'
+
+	local uci = require('simple-uci').cursor()
 
 	local translations = {}
 	local site_i18n = i18n 'gluon-site'
@@ -35,22 +39,22 @@
 		return interfaces
 	end
 
-	local function get_radios(uconn)
-		local radios = uconn:call("network.wireless", "status", {})
+	local function get_radios()
 		local ret = {}
 
-		for radio, info in pairs(radios) do
-			if info.up then
+		wireless.foreach_radio(uci, function(radio)
+			local channel = iwinfo.nl80211.channel(wireless.find_phy(radio))
+			if channel then
 				table.insert(ret, {
-					name = radio,
-					channel = info.config.channel,
+					name = radio['.name'],
+					channel = channel,
 				})
 			end
-		end
-
+		end)
 		table.sort(ret, function(a, b)
 			return a.name < b.name
 		end)
+
 		return ret
 	end
 
@@ -72,10 +76,11 @@
 	end
 
 	local interfaces = get_interfaces(uconn)
-	local radios = get_radios(uconn)
 
 	ubus.close(uconn)
 
+	local radios = get_radios()
+
 	local function sorted(t)
 		t = {unpack(t)}
 		table.sort(t)