tests: adjust tests for Dovecot 2.4

Dovecot 2.4 (used in Debian trixie) changed its configuration
significantly. Have two sections for the old and the new version.

QubesOS/qubes-issues#8841

Author: marmarek

splitgpg2tests/tests.py

@@ -370,9 +370,14 @@ def setUp(self):
 
         # IMAP configuration
         self.imap_pw = "pass"
-        self.frontend.run(
-            'echo "mail_location=maildir:~/Mail\nuserdb {\n driver = passwd\n}\npassdb {\n driver = static\n args = password=pass\n}" |\
-                tee /etc/dovecot/conf.d/100-mail.conf', wait=True, user="root")
+        if self.frontend.run("grep -q mail_driver /etc/dovecot/conf.d/10-mail.conf", wait=True) == 0:
+            self.frontend.run(
+                'echo "mail_driver = maildir\nmail_path = ~/Mail\nmail_inbox_path = ~/Mail\nuserdb static {\n driver = passwd\n}\npassdb static {\n driver = static\n password=pass\n}" |\
+                    tee /etc/dovecot/conf.d/100-mail.conf', wait=True, user="root")
+        else:
+            self.frontend.run(
+                'echo "mail_location=maildir:~/Mail\nuserdb {\n driver = passwd\n}\npassdb $db_name {\n driver = static\n args = password=pass\n}" |\
+                    tee /etc/dovecot/conf.d/100-mail.conf', wait=True, user="root")
         self.frontend.run(
             "sed -i 's/^!include/#\\0/' /etc/dovecot/conf.d/10-auth.conf",
             wait=True, user="root")