Add license header for allVL1.m

Ref. #1689
9 jobs for master in 71 minutes and 43 seconds (queued for 1 second)
latest
Status Job ID Name Coverage
  Build
passed #13689
build_binaries

00:12:18

passed #13690
build_doc

00:01:29

 
  Test And Pkg
passed #13693
macOS
pkg_macOS

00:13:32

passed #13691
pkg_source

00:03:03

passed #13692
pkg_windows

00:32:36

passed #13697
test_dynare++

00:16:15

passed #13694
test_matlab

00:58:54

manual #13696
allowed to fail manual
test_octave
manual #13695
allowed to fail manual
test_old_matlab