Improvement: Get rid of ESLint warning in drawers.mustache

[abias]

ESLint started to complain about a change in drawers.mustache:

theme/boost_union/templates/theme_boost/drawers.mustache
    [(#1) ESLint warning [no-multiple-empty-lines]: More than 2 blank lines not allowed. ( }); ), Line: 22 Column: 1](https://git.in.moodle.com/pluginsbot/moodle-plugins-snapshots/blob/83d8efeae73506e4b11a22f4c9c62f4e32128013/theme/boost_union/templates/theme_boost/drawers.mustache#L1)

This seems to be caused by this code:

{{#js}}
M.util.js_pending('theme_boost/loader');
require(['theme_boost/loader', 'theme_boost/drawer'{{#regions.offcanvas.hasblocks}},'theme_boost_union/offcanvas'{{/regions.offcanvas.hasblocks}}{{#includesmartmenu}}, 'theme_boost_union/smartmenu'{{/includesmartmenu}}{{#blockregionsdata.includeblockregionsamd}}, 'theme_boost_union/blockregions'{{/blockregionsdata.includeblockregionsamd}}], function(Loader, Drawer{{#regions.offcanvas.hasblocks}},OffCanvas{{/regions.offcanvas.hasblocks}}{{#includesmartmenu}}, SmartMenu{{/includesmartmenu}}{{#blockregionsdata.includeblockregionsamd}}, BlockRegions{{/blockregionsdata.includeblockregionsamd}}) {
    Drawer.init();
    M.util.js_complete('theme_boost/loader');
{{#regions.offcanvas.hasblocks}}OffCanvas.init();{{/regions.offcanvas.hasblocks}}
{{#includesmartmenu}}SmartMenu.init();{{/includesmartmenu}}
{{#blockregionsdata.outsideregions.verticaloffset}}BlockRegions.OutsideRegionsVerticalAlignment();{{/blockregionsdata.outsideregions.verticaloffset}}
});
{{/js}}

and the fact that, if this template is rendered, there might be 3 empty lines at the end of the Javascript section.