MINOR: Remove training whitespace.

The main benefit of this is so that authors who make use of
.editorconfig don't end up with whitespace changes in their PRs.

Spaces vs. tabs has been left alone, although that could do with a
tidy-up in SS4 after the switch to PSR-1/2.

The command used was this:

for match in '*.ss' '*.css' '*.scss' '*.html' '*.yml' '*.php' '*.js' '*.csv' '*.inc' '*.php5'; do
	find . -path ./thirdparty -prune -o -type f -name "$match" -exec sed -i '' 's/[[:space:]]\+$//' {} \+
	find . -path ./thirdparty -prune -o -type f -name "$match" | xargs perl -pi -e 's/ +$//'
done

javascript/AssetAdmin.DragDrop.js

@@ -69,8 +69,8 @@
 					appendTo: 'body',
 					helper: function() {
 						return $(
-							'<div class="NumFilesIndicator">' +
-							ss.i18n.sprintf(ss.i18n._t('AssetTableField.MOVING'),container.getSelected().length) +
+							'<div class="NumFilesIndicator">'
+							ss.i18n.sprintf(ss.i18n._t('AssetTableField.MOVING'),container.getSelected().length)
 							'</div>'
 						);
 					}