Disabled galera_ist_progress at it always fails in 10.2

mysql-test/include/assert_grep.inc

@@ -130,7 +130,10 @@ EOF
 --let $_ag_outcome= `SELECT LOAD_FILE('$_AG_OUT')`
 if ($_ag_outcome != 'assert_grep.inc ok')
 {
-  --source include/show_rpl_debug_info.inc
+  if ($rpl_server_count != '')
+  {
+    --source include/show_rpl_debug_info.inc
+  }
   --echo include/assert_grep.inc failed!
   --echo assert_text: '$assert_text'
   --echo assert_file: '$assert_file'

mysql-test/suite/galera/disabled.def

@@ -59,4 +59,5 @@ MW-328C: MDEV-13549 Galera test failures 10.1
 MW-328A: MDEV-13549 Galera test failures 10.1
 MW-328B: MDEV-13549 Galera test failures 10.1
 MW-328: MDEV-13549 Galera test failures 10.1
-galera_suspend_slave: MDEV-13549 Galera test failures 10.1
+galera_suspend_slave: MDEV-13549 Galera test failures 10.1
\ No newline at end of file
+galera_ist_progress: MDEV-15236 galera_ist_progress fails when trying to read transfer status