Don't double save nodeDB on shutdown

src/Power.cpp

@@ -700,7 +700,7 @@ void Power::shutdown()
 #ifdef PIN_LED3
     ledOff(PIN_LED3);
 #endif
-    doDeepSleep(DELAY_FOREVER, false, false);
+    doDeepSleep(DELAY_FOREVER, false, true);
 #elif defined(ARCH_PORTDUINO)
     exit(EXIT_SUCCESS);
 #else

src/shutdown.h

@@ -41,6 +41,7 @@ void powerCommandsCheck()
     }
 
     if (shutdownAtMsec && millis() > shutdownAtMsec) {
+        shutdownAtMsec = 0;
         power->shutdown();
     }
 }