revert if condition for AccountAuthenticator

Signed-off-by: alperozturk <alper_ozturk@proton.me>

app/src/main/java/com/owncloud/android/authentication/AccountAuthenticator.java

@@ -71,7 +71,7 @@ public class AccountAuthenticator extends AbstractAccountAuthenticator {
 
         final Bundle bundle = new Bundle();
 
-        if (accounts.length > 1 && MDMConfig.INSTANCE.multiAccountSupport(mContext)) {
+        if (accounts.length < 1 || MDMConfig.INSTANCE.multiAccountSupport(mContext)) {
             try {
                 validateAccountType(accountType);
             } catch (AuthenticatorException e) {