Filter out obviously broken URLs from default route

[racke]

265 Query SELECT COUNT( * ) FROM products me WHERE ( uri = 'img/.jpg' )
265 Query SELECT COUNT( * ) FROM products me WHERE ( uri = 'img/.jpg' )
265 Query SELECT me.sku, me.name, me.short_description, me.description, me.price, me.uri, me.weight, me.priority, me.gtin, me.canonical_sku, me.active, me.inventory_exempt FROM products me WHERE ( me.sku = 'img/.jpg' )