Bsongis/wizard issue when model id already used (#7259)

Wizard: popup displayed when modelID already used, but screen not refreshed

radio/src/main.cpp

@@ -469,9 +469,9 @@ void guiMain(event_t evt)
 
   lcdRefresh();
 
-  if (mainRequestFlags & (1 << REQUEST_SCREENSHOT)) {
+  if (mainRequestFlags & (1u << REQUEST_SCREENSHOT)) {
     writeScreenshot();
-    mainRequestFlags &= ~(1 << REQUEST_SCREENSHOT);
+    mainRequestFlags &= ~(1u << REQUEST_SCREENSHOT);
   }
 }
 #endif