* HeltecV3: powerOff() fix

src/helpers/HeltecV3Board.h

@@ -85,8 +85,7 @@ public:
   }
 
   void powerOff() override {
-    // TODO: re-enable this when there is a definite wake-up source pin:
-    //  enterDeepSleep(0);
+    enterDeepSleep(0);
   }
 
   uint16_t getBattMilliVolts() override {