[6.x] [i18n] Move welcome error message from a script insertion to a data attribute (#29581)#29605

maryia-lapata merged 2 commits intoelastic:6.xelastic/kibana:6.xfrom

maryia-lapata:backport/6.x/pr-29581maryia-lapata/kibana:backport/6.x/pr-29581Copy head branch name to clipboard