update default AP channel to 6, possible fix for "AP does not show"

backport from upstream

Author: softhack007

wled00/wled.h

@@ -348,7 +348,7 @@ WLED_GLOBAL char clientSSID[33] _INIT(CLIENT_SSID);
 WLED_GLOBAL char clientPass[65] _INIT(CLIENT_PASS);
 WLED_GLOBAL char cmDNS[33] _INIT(MDNS_NAME);                       // mDNS address (*.local, replaced by wledXXXXXX if default is used)
 WLED_GLOBAL char apSSID[33] _INIT("");                             // AP off by default (unless setup)
-WLED_GLOBAL byte apChannel _INIT(1);                               // 2.4GHz WiFi AP channel (1-13)
+WLED_GLOBAL byte apChannel _INIT(6);                               // 2.4GHz WiFi AP channel (1-13)
 WLED_GLOBAL byte apHide    _INIT(0);                               // hidden AP SSID
 WLED_GLOBAL byte apBehavior _INIT(AP_BEHAVIOR_BOOT_NO_CONN);       // access point opens when no connection after boot by default
 WLED_GLOBAL IPAddress staticIP      _INIT_N(((  0,   0,  0,  0))); // static IP of ESP