Gantry 5.5(J! 4): Improve the popup message on Session Expired

[tonamphong]

If the session is expired, clicking on particle settings and you will get the popup message like [object Object]. Could you please correct it?

Images compared between J3 and J4

J3

J4

[mahagr]

@hexplor Can you recompile JS and commit?

[mahagr]

Looks like the above fix is only partial; more work is needed to fix the issue everywhere.