wifi-scripts: sync enable_background_radar in ucode with old version

It needs to be opt-in instead of opt-out, since there is no reliable way to
determine if the extra background radar chain has an antenna connected.

Signed-off-by: Felix Fietkau <[email protected]>

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

@@ -493,7 +493,7 @@ function generate(config) {
 	if (!phy_features.radar_background || config.band != '5g')
 		delete config.enable_background_radar;
 	else
-		set_default(config, 'enable_background_radar', phy_features.radar_background);
+		set_default(config, 'enable_background_radar', false);
 
 	append_vars(config, [ 'acs_chan_bias', 'acs_exclude_dfs', 'enable_background_radar' ]);