Clarified address regex

src/node/src/client.js

@@ -548,8 +548,8 @@ exports.makeClientConstructor = function(methods, serviceName) {
     }
     options['grpc.primary_user_agent'] = 'grpc-node/' + version;
     this.channel = new grpc.Channel(address, credentials, options);
-    // Extract the DNS name from the address string
+    // Remove the optional DNS scheme, trailing port, and trailing backslash
-    address = address.replace(/(\w+:\/\/+)?([^:]+)(:\d+)?\/?$/, '$2');
+    address = address.replace(/^(dns:\/{3})?([^:\/]+)(:\d+)?\/?$/, '$2');
     this.server_address = address;
     this.auth_uri = 'https://' + this.server_address + '/' + serviceName;
     this.updateMetadata = updateMetadata;