fix(build): Fix MDNS Guard name

Author: me-no-dev

Diff for: libraries/ESPmDNS/src/ESPmDNS.cpp

@@ -39,7 +39,7 @@ License (MIT license):
 #endif
 
 #include "ESPmDNS.h"
-#ifdef MDNS_MAX_INTERFACES
+#ifdef CONFIG_MDNS_MAX_INTERFACES
 #include <functional>
 #include "esp_mac.h"
 #include "soc/soc_caps.h"
@@ -393,4 +393,4 @@ String MDNSResponder::txtKey(int idx, int txtIdx) {
 
 MDNSResponder MDNS;
 
-#endif /* MDNS_MAX_INTERFACES */
+#endif /* CONFIG_MDNS_MAX_INTERFACES */

Diff for: libraries/ESPmDNS/src/ESPmDNS.h

@@ -42,7 +42,7 @@ License (MIT license):
 #define ESP32MDNS_H
 
 #include "sdkconfig.h"
-#ifdef MDNS_MAX_INTERFACES
+#ifdef CONFIG_MDNS_MAX_INTERFACES
 
 #include "Arduino.h"
 #include "mdns.h"
@@ -128,5 +128,5 @@ class MDNSResponder {
 
 extern MDNSResponder MDNS;
 
-#endif /* MDNS_MAX_INTERFACES */
+#endif /* CONFIG_MDNS_MAX_INTERFACES */
 #endif  //ESP32MDNS_H