Single account is primary

app/src/main/java/eu/faircode/email/FairEmailBackupAgent.java

@@ -208,6 +208,13 @@ public class FairEmailBackupAgent extends BackupAgent {
                                         db.account().getAccountByUUID(account.uuid) != null)
                                     continue;
 
+                                if (jaccounts.length() == 1)
+                                    account.primary = true;
+
+                                EntityAccount primary = db.account().getPrimaryAccount();
+                                if (primary != null)
+                                    account.primary = false;
+
                                 if (account.auth_type == ServiceAuthenticator.AUTH_TYPE_GMAIL)
                                     account.synchronize = false;
 

app/src/main/java/eu/faircode/email/FragmentOptionsBackup.java

@@ -947,6 +947,9 @@ public class FragmentOptionsBackup extends FragmentBase implements SharedPrefere
                             Long aid = account.id;
                             account.id = null;
 
+                            if (jaccounts.length() == 1)
+                                account.primary = true;
+
                             EntityAccount primary = db.account().getPrimaryAccount();
                             if (primary != null)
                                 account.primary = false;