Adds azureProperty property to handle backward compatibility when using the isBinary property

lib/backends/azure-keyvault-backend.js

@@ -36,7 +36,10 @@ class AzureKeyVaultBackend extends KVBackend {
     const secret = await client.getSecret(key)
     // Handle binary files, since the Azure client does not
     if (keyOptions && keyOptions.isBinary) {
-      return Buffer.from(secret.value, 'base64')
+      if (!keyOptions.azureProperty) {
+        keyOptions.azureProperty = 'value'
+      }
+      return Buffer.from(secret[keyOptions.azureProperty], 'base64')
     }
     return JSON.stringify(secret)
   }