AccountImporter: Remove unnecessary cast

Change-Id: Ie7a7fb553da36f704db91cf05ef939c95e7f1b7a

github-plugin/src/main/java/com/google/gerrit/server/account/AccountImporter.java

diff --git a/github-plugin/src/main/java/com/google/gerrit/server/account/AccountImporter.java b/github-plugin/src/main/java/com/google/gerrit/server/account/AccountImporter.java
index 25ff9e2..648afbb 100644
--- a/github-plugin/src/main/java/com/google/gerrit/server/account/AccountImporter.java
+++ b/github-plugin/src/main/java/com/google/gerrit/server/account/AccountImporter.java
@@ -55,8 +55,7 @@
       accountInput.username = login;
       accountInput.name = MoreObjects.firstNonNull(name, login);
       Response<AccountInfo> accountResponse =
-          (Response<AccountInfo>) createAccount.apply(TopLevelResource.INSTANCE,
-              accountInput);
+          createAccount.apply(TopLevelResource.INSTANCE, accountInput);
       if (accountResponse.statusCode() == HttpStatus.SC_CREATED) {
         Id accountId = new Account.Id(accountResponse.value()._accountId);
         db.accountExternalIds().insert(