Bugfix on escape character

TASMAN-core/src/main/java/it/inaf/ia2/tsm/datalayer/DBBrokerTemplate.java

@@ -918,7 +918,9 @@ public abstract class DBBrokerTemplate implements DBBroker {
         sb.append("SELECT k.key_id AS key_id\n");
         sb.append("FROM ");
         sb.append(tapSchemaName);
-        sb.append(".`keys` k\n");
+        sb.append(".");
+        sb.append(escape("keys"));
+        sb.append(" k\n");
         sb.append("JOIN ");
         sb.append(tapSchemaName);
         sb.append(".key_columns c ON k.key_id = c.key_id\n");