server: Add index field to transactions table

The transaction order from the xsnd must be recoverable
when we store the transactions in the database.

server/conf/evolutions/default/9.sql

@@ -0,0 +1,11 @@
+
+# --- !Ups
+
+ALTER TABLE transactions
+ADD COLUMN index NON_NEGATIVE_INT_TYPE NULL DEFAULT NULL;
+
+
+# --- !Downs
+
+ALTER TABLE transactions
+DROP COLUMN index;