Add servername option to RabbitMQ for better SNI certificate selection

This fix allows to better mitigate ERROR: unable to verify the first certificate.

For more information see amqp-node/amqplib#331

packages/nodes-base/credentials/RabbitMQ.credentials.ts

@@ -122,6 +122,20 @@ export class RabbitMQ implements ICredentialType {
 			default: '',
 			description: 'SSL CA Certificates to use.',
 		},
+		{
+			displayName: 'Server Name',
+			name: 'servername',
+			type: 'string' as NodePropertyTypes,
+			displayOptions: {
+				show: {
+					ssl: [
+						true,
+					],
+				},
+			},
+			default: '',
+			placeholder: 'localhost',
+		},
 		// {
 		// 	displayName: 'Client ID',
 		// 	name: 'clientId',

packages/nodes-base/nodes/RabbitMQ/GenericFunctions.ts

@@ -15,6 +15,7 @@ export async function rabbitmqConnect(this: IExecuteFunctions | ITriggerFunction
 		'username',
 		'password',
 		'vhost',
+		'servername'
 	];
 
 	const credentialData: IDataObject = {};
@@ -30,6 +31,7 @@ export async function rabbitmqConnect(this: IExecuteFunctions | ITriggerFunction
 		optsData.key = credentials.key === '' ? undefined : Buffer.from(credentials.key as string);
 		optsData.passphrase = credentials.passphrase === '' ? undefined : credentials.passphrase;
 		optsData.ca = credentials.ca === '' ? undefined : [Buffer.from(credentials.ca as string)];
+		optsData.servername = credentials.servername === '' ? undefined : credentials.servername;
 		optsData.credentials = amqplib.credentials.external();
 	}