Editor: fixes scripts container layout error.

[linbingquan]

I created a script for Mesh, and then delete it, but script = [], I add condition for scriptsContainer.

[mrdoob]

Nice catch!

[mrdoob]

I think you can just do this though?

if ( scripts !== undefined && scripts.length > 0 ) {

[linbingquan]

I think you can just do this though?

if ( scripts !== undefined && scripts.length > 0 ) {

@mrdoob 932b623

[mrdoob]

Thanks!