Add mastodon and display admin email in the contact page

server.js

@@ -18,6 +18,11 @@ try {
     console.log("You can customize the configuration by copying config/config.example.js to config/config.js");
     config = require('./config/config.example');
 }
+
+if (config.adminEmail === 'i.did.not.read.my.config@cryptpad.fr') {
+    console.log("You can configure the administrator email (adminEmail) in your config/config.js file");
+}
+
 var websocketPort = config.websocketPort || config.httpPort;
 var useSecureWebsockets = config.useSecureWebsockets || false;