Revert welcome.c and fix default keepAlive to 3 (PR #218)

App/screenshot.c

@@ -26,7 +26,7 @@
 // - No currentFrame or deltaFrame static buffers
 static uint8_t previousFrame[1024] = {0};
 static uint8_t forcedBlock = 0;
-static uint8_t keepAlive = 0;
+static uint8_t keepAlive = 3;
 
 void SCREENSHOT_ParseInput(void)
 {

App/ui/welcome.c

@@ -221,8 +221,8 @@ void UI_DisplayWelcome(void)
         //ST7565_BlitStatusLine();  // blank status line : I think it's useless
         ST7565_BlitFullScreen();
 
-        // #ifdef ENABLE_FEAT_F4HWN_SCREENSHOT
-        //     SCREENSHOT_Update(true);   // I think that's useless too
-        // #endif
+        #ifdef ENABLE_FEAT_F4HWN_SCREENSHOT
+            SCREENSHOT_Update(true);
+        #endif
     }
 }