prevent flickering during OTA

I've almost toasted my wiring due to uncontrolled LED flickering during OTA.
So here is the fix - it prevents any strip updates when OTA is ongoing.

wled00/FX_fcn.cpp

@@ -1615,6 +1615,8 @@ void WS2812FX::waitUntilIdle(void) {
 
 void WS2812FX::service() {
   unsigned long nowUp = millis(); // Be aware, millis() rolls over every 49 days // WLEDMM avoid losing precision
+  if (OTAisRunning) return; // WLEDMM avoid flickering during OTA
+
   now = nowUp + timebase;
   #if defined(ARDUINO_ARCH_ESP32) && defined(WLEDMM_FASTPATH)
     if ((_frametime > 2) && (_frametime < 32) && (nowUp - _lastShow) < (_frametime/2)) return;  // WLEDMM experimental - stabilizes frametimes but increases CPU load
@@ -1776,6 +1778,8 @@ void WS2812FX::estimateCurrentAndLimitBri() {
 }
 
 void WS2812FX::show(void) {
+  if (OTAisRunning) return; // WLEDMM avoid flickering during OTA
+
   // avoid race condition, capture _callback value
   show_callback callback = _callback;
   if (callback) callback();

wled00/wled.h

@@ -8,7 +8,7 @@
  */
 
 // version code in format yymmddb (b = daily build)
-#define VERSION 2401290
+#define VERSION 2402120
 
 // WLEDMM  - you can check for this define in usermods, to only enabled WLEDMM specific code in the "right" fork. Its not defined in AC WLED.
 #define _MoonModules_WLED_
@@ -749,6 +749,7 @@ WLED_GLOBAL volatile bool doInitBusses _INIT(false);        // WLEDMM "volatile"
 WLED_GLOBAL volatile bool loadLedmap _INIT(false);          // WLEDMM use as bool and use loadedLedmap for Nr
 WLED_GLOBAL volatile uint8_t loadedLedmap _INIT(0);         // WLEDMM default 0
 WLED_GLOBAL volatile bool suspendStripService _INIT(false); // WLEDMM temporarily prevent running strip.service, when strip or segments are "under update" and inconsistent
+WLED_GLOBAL volatile bool OTAisRunning _INIT(false);        // WLEDMM temporarily stop led updates during OTA
 #ifndef ESP8266
 WLED_GLOBAL char  *ledmapNames[WLED_MAX_LEDMAPS-1] _INIT_N(({nullptr}));
 #endif

wled00/wled_server.cpp

@@ -336,6 +336,8 @@ void initServer()
     if(!index){
       DEBUG_PRINTLN(F("OTA Update Start"));
       WLED::instance().disableWatchdog();
+      OTAisRunning = true; // WLEDMM flicker fixer
+      strip.fill(BLACK);
       usermods.onUpdateBegin(true); // notify usermods that update is about to begin (some may require task de-init)
       lastEditTime = millis(); // make sure PIN does not lock during update
       #ifdef ESP8266
@@ -352,6 +354,7 @@ void initServer()
         usermods.onUpdateBegin(false); // notify usermods that update has failed (some may require task init)
         WLED::instance().enableWatchdog();
       }
+      OTAisRunning = false; // WLEDMM flicker fixer
     }
   });
 #else