0004167: sym_router table should require router_type value

symmetric-core/src/main/resources/symmetric-schema.xml

@@ -739,7 +739,7 @@
         <column name="target_table_name" type="VARCHAR" size="255"  description="Optional name for a target table.  Only use this if the target table name is different than the source." />
         <column name="source_node_group_id" type="VARCHAR" size="50" required="true"  description="Routers with this node_group_id will install triggers that are mapped to this router." />
         <column name="target_node_group_id" type="VARCHAR" size="50" required="true"  description="The node_group_id for nodes to route data to.  Note that routing can be further narrowed down by the configured router_type and router_expression." />
-        <column name="router_type" type="VARCHAR" size="50"  description="The name of a specific type of router.  Out of the box routers are 'default','column','bsh', 'subselect' and 'audit.'  Custom routers can be configured as extension points." />
+        <column name="router_type" type="VARCHAR" size="50" required="true" default="default" description="The name of a specific type of router.  Out of the box routers are 'default','column','bsh', 'subselect' and 'audit.'  Custom routers can be configured as extension points." />
         <column name="router_expression" type="LONGVARCHAR"  description="An expression that is specific to the type of router that is configured in router_type.  See the documentation for each router for more details." />
         <column name="sync_on_update" type="BOOLEANINT" size="1" required="true" default="1"  description="Flag that indicates that this router should route updates." />
         <column name="sync_on_insert" type="BOOLEANINT" size="1" required="true" default="1"  description="Flag that indicates that this router should route inserts." />