test: schedule test logins on correct day

As the current time is moving on throught the test, the calculation of "n days
ago" ends up picking a time which is slightly more than "n days ago", so reduce
n by one. This error was mostly neutralised by the rotation threshold throwing
away microseconds, but with that fixed, the tests always fail unless this is
also fixed.

tests/tst-login-logout.c

@@ -184,26 +184,26 @@ main(void)
   /* make sure there is no old stuff flying around. The backup file is not so important. */
   remove (db_path);
 
-  if (test_args (db_path, "user1", "test-tty", "localhost", NULL, 4) != 0)
+  if (test_args (db_path, "user1", "test-tty", "localhost", NULL, 3) != 0)
     return 1;
-  if (test_args (db_path, "user2", NULL, NULL, NULL, 4) != 0)
+  if (test_args (db_path, "user2", NULL, NULL, NULL, 3) != 0)
     return 1;
-  if (test_args (db_path, "user3", NULL, NULL, NULL, 4) != 0)
+  if (test_args (db_path, "user3", NULL, NULL, NULL, 3) != 0)
     return 1;
-  if (test_args (db_path, "user4", "test-tty", NULL, NULL, 4) != 0)
+  if (test_args (db_path, "user4", "test-tty", NULL, NULL, 3) != 0)
     return 1;
-  if (test_args (db_path, "user5", NULL, "localhost", NULL, 4) != 0)
+  if (test_args (db_path, "user5", NULL, "localhost", NULL, 3) != 0)
     return 1;
 
-  if (test_args (db_path, "user1", "test-tty", "localhost", NULL, 3) != 0)
+  if (test_args (db_path, "user1", "test-tty", "localhost", NULL, 2) != 0)
     return 1;
-  if (test_args (db_path, "user2", NULL, NULL, NULL, 3) != 0)
+  if (test_args (db_path, "user2", NULL, NULL, NULL, 2) != 0)
     return 1;
-  if (test_args (db_path, "user3", NULL, NULL, NULL, 3) != 0)
+  if (test_args (db_path, "user3", NULL, NULL, NULL, 2) != 0)
     return 1;
-  if (test_args (db_path, "user4", "test-tty", NULL, NULL, 3) != 0)
+  if (test_args (db_path, "user4", "test-tty", NULL, NULL, 2) != 0)
     return 1;
-  if (test_args (db_path, "user5", NULL, "localhost", NULL, 3) != 0)
+  if (test_args (db_path, "user5", NULL, "localhost", NULL, 2) != 0)
     return 1;
 
   if (test_rotate (db_path, 3) != 0)