Apply suggestions from code review

Co-authored-by: Hiroyuki Yamada <[email protected]>

Author: KodaiD

core/src/main/java/com/scalar/db/common/CoreError.java

@@ -709,7 +709,7 @@ public enum CoreError implements ScalarDbError {
   CASSANDRA_RENAME_NON_PRIMARY_KEY_COLUMN_NOT_SUPPORTED(
       Category.USER_ERROR,
       "0222",
-      "Cassandra does not support renaming the non-primary key column feature",
+      "Cassandra does not support renaming non-primary key columns",
       "",
       ""),