fixed 13a08f30 from https://gitee.com/sun-yue14/docs/pulls/2628

update en/application-dev/reference/apis/js-apis-appAccount.md.
Signed-off-by: Nsunyue <sunyue77@h-partners.com>

en/application-dev/reference/apis/js-apis-appAccount.md

@@ -387,7 +387,7 @@ Checks whether an app account allows application data synchronization. This meth
 
 ### setAccountCredential
 
-setAccountCredential(name: string, credentialType: string, credential: string,callback: AsyncCallback<void>): void
+setAccountCredential(name: string, credentialType: string, credential: string callback: AsyncCallback<void>): void
 
 Sets a credential for an app account. This method uses an asynchronous callback to return the result.