fix: service key for getContentstackEndpoint method

Author: nadeem-cs

lib/contentstack.js

@@ -172,7 +172,7 @@ import { getContentstackEndpoint } from '@contentstack/utils'
  */
 export function client (params = {}) {
   let defaultHostName = params.region
-    ? getContentstackEndpoint(params.region.toUpperCase(), 'management', true)
+    ? getContentstackEndpoint(params.region.toUpperCase(), 'contentManagement', true)
     : getContentstackEndpoint('NA', 'contentManagement', true)
 
   if (params.host) {