wifi-scripts: iwinfo.uc: fix null reference in info()

Fixes: https://github.com/openwrt/openwrt/issues/21651
Signed-off-by: Felix Fietkau <[email protected]>
(cherry picked from commit 434e1461b293e4c014391dd19d3977b193a2166f)

package/network/config/wifi-scripts/files-ucode/usr/share/ucode/iwinfo.uc

@@ -445,7 +445,7 @@ export function info(name) {
 		};
 
 		let phy = find_phy(data.wiphy);
-		for (let limit in phy.interface_combinations[0]?.limits)
+		for (let limit in phy.interface_combinations?.[0]?.limits)
 			if (limit.types?.ap && limit.max > 1)
 				dev.vaps = 'yes';