small changes to retry failed by timeout CI

Author: mkorolyov

database/cassandra/README.md

@@ -1,7 +1,7 @@
 # Cassandra / ScyllaDB
 
 * Drop command will not work on Cassandra 2.X because it rely on
-system_schema table which comes with 3.X. Works as expected for ScyllaDB.
+system_schema table which comes with 3.X. Works for ScyllaDB.
 * Other commands should work properly but are **not tested**
 * The Cassandra driver (gocql) does not natively support executing multiple statements in a single query. To allow for multiple statements in a single migration, you can use the `x-multi-statement` param. There are two important caveats:
   * This mode splits the migration text into separately-executed statements by a semi-colon `;`. Thus `x-multi-statement` cannot be used when a statement in the migration contains a string with a semi-colon.