SimpleMDNS: let begin return a bool (earlephilhower#2599)

SimpleMDNS: let `begin` return a bool
To be compatible with LEAmDNS

Author: GUVWAF

libraries/SimpleMDNS/src/SimpleMDNS.cpp

@@ -24,9 +24,9 @@
 #include <LwipEthernet.h>
 #include <lwip/apps/mdns.h>
 
-void SimpleMDNS::begin(const char *hostname, unsigned int ttl) {
+bool SimpleMDNS::begin(const char *hostname, unsigned int ttl) {
     if (_running) {
-        return;
+        return false;
     }
     mdns_resp_init();
     struct netif *n = netif_list;
@@ -37,6 +37,8 @@ void SimpleMDNS::begin(const char *hostname, unsigned int ttl) {
     __setStateChangeCallback(_statusCB);
     _hostname = strdup(hostname);
     _running = true;
+
+    return true;
 }
 
 void SimpleMDNS::enableArduino(unsigned int port, bool passwd) {

libraries/SimpleMDNS/src/SimpleMDNS.h

@@ -25,7 +25,7 @@
 class SimpleMDNS {
 
 public:
-    void begin(const char *hostname, unsigned int ttl = 60);
+    bool begin(const char *hostname, unsigned int ttl = 60);
     void enableArduino(unsigned int port, bool passwd = false);
     void addService(const char *service, const char *proto, unsigned int port);