reduce dBm to 15dBm for all, for now, will need to ifdef guard

Author: brentru

src/network_interfaces/Wippersnapper_ESP32.h

@@ -103,6 +103,8 @@ class Wippersnapper_ESP32 : public Wippersnapper {
     WiFi.disconnect();
     delay(100);
 
+    WiFi.setTxPower(WIFI_POWER_15dBm);
+
     // Perform a network scan
     int n = WiFi.scanNetworks();
     if (n == 0) {