Ignore ORCA optimizer version in isolation2 tests

The modify_table_data_corrupt test failed due to difference in the ORCA version
string. So ignore it by adding the pattern in the isolation2 init_file.

src/test/isolation2/init_file_isolation2

@@ -44,3 +44,8 @@ s/^Process \d+ waits for ShareLock on transaction \d+; blocked by process \d+./P
 m/available \d+ MB/
 s/available \d+ MB//
 -- end_matchsubs
+
+
+-- start_matchignore
+m/^ Optimizer: Pivotal Optimizer \(GPORCA\) version .*/
+-- end_matchignore