themes/bootstrap: make theme usable on touchscreen

When using this theme on touchscreen, after selecting menu it won't
allow me select submenu selection. It directly start loading menu
section (unnecessary, because it's always first link in subsection).
It work only at moment, when you are really fast, which is annoying.

Signed-off-by: David Heidelberger <david.heidelberger@ixit.cz>
Merge pull request #222 from iXit/master

themes/bootstrap: make theme usable on touchscreen