Don't create thumbnail for multi-URL pastes

When multiple URLs are pasted at once, a thumbnail is automatically created for the first link. This obscures the presence of additional URLs and makes the paste appear identical to a single-URL tile. This can be annoying if I have other single URL tiles and need to distinguish which is which.

For example, I sometimes combine several individually copied URLs into a single tile to groupt a set of links I need to paste multiple times. However, the grouped tile looks identical to a single-link tile, making it difficult to distinguish between a collection of links and an individual URL if they get mixed up.