fix bad implementation, try to redefine constant variable

* fix error: passing const string as this argument discards qualifiers
  for server list identification id
* related commit 90573105519953847be513068c1f05f1a1771d7c

src/server.cpp

@@ -3304,7 +3304,7 @@ std::string Server::getStatusString()
 
 	os << "# Server: ";
 	// Version
-	if (!g_settings->getBool("announce_mt_id").empty())
+	if (!g_settings->getBool("announce_mt_id"))
 	os << "version=" << "0.4.16";
 	else
 	os << "version=" << g_version_string;

src/serverlist.cpp

@@ -118,25 +118,26 @@ void sendAnnounce(AnnounceAction action,
 			server["lag"] = lag;
 	}
 
-	const std::string json;
+	const std::string json1;
+	const std::string json2;
 	if (g_settings->getBool("announce_mt_url")) {
 		if (g_settings->getBool("announce_mt_id")) {
 			server["version"]      = "0.4.16";//g_version_string;
 			server["server_id"]    = "minetest";
 		}
-		json = fastWriteJson(server);
-		sendAnnounceInner(action, json, base64_decode("c2VydmVycy5taW5ldGVzdC5uZXQ"));
+		json1 = fastWriteJson(server);
+		sendAnnounceInner(action, json1, base64_decode("c2VydmVycy5taW5ldGVzdC5uZXQ"));
 		server["version"]      = g_version_string;
 		server["server_id"]    = "multicraft";
-		json = fastWriteJson(server);
-		sendAnnounceInner(action, json, base64_decode("c2VydmVycy5tdWx0aWNyYWZ0Lndvcmxk"));
+		json2 = fastWriteJson(server);
+		sendAnnounceInner(action, json2, base64_decode("c2VydmVycy5tdWx0aWNyYWZ0Lndvcmxk"));
 	} else {
-		json = fastWriteJson(server);
-		sendAnnounceInner(action, json, g_settings->get("serverlist_url"));
+		json1 = fastWriteJson(server);
+		sendAnnounceInner(action, json1, g_settings->get("serverlist_url"));
 		server["version"]      = g_version_string;
 		server["server_id"]    = "multicraft";
-		json = fastWriteJson(server);
-		sendAnnounceInner(action, json, base64_decode("c2VydmVycy5tdWx0aWNyYWZ0Lndvcmxk"));
+		json2 = fastWriteJson(server);
+		sendAnnounceInner(action, json2, base64_decode("c2VydmVycy5tdWx0aWNyYWZ0Lndvcmxk"));
 	}
 }
 #endif