Merge pull request #5157 from nextcloud/ezaquarii/fix-npe-in-get-user-in-user-account-manager

Fix NPE in UserAccountManagerImpl.getUser(CharSequence)

scripts/analysis/findbugs-results.txt

@@ -1 +1 @@
-414
+413

src/main/java/com/nextcloud/client/account/UserAccountManagerImpl.java

@@ -227,7 +227,7 @@ public class UserAccountManagerImpl implements UserAccountManager {
     public Optional<User> getUser(CharSequence accountName) {
         Account account = getAccountByName(accountName.toString());
         User user =  createUserFromAccount(account);
-        return Optional.of(user);
+        return Optional.ofNullable(user);
     }
 
     @Override