by Stefano.Rausch on Fri Feb 22, 2013 9:37 pm
Looking at the default settings you'll find the following entry:
// By default, shift+tab will only unindent if the selection spans
// multiple lines. When pressing shift+tab at other times, it'll insert a
// tab character - this allows tabs to be inserted when tab_completion is
// enabled. Set this to true to make shift+tab always unindent, instead of
// inserting tabs.
"shift_tab_unindent": false,
HTH