Move delta

`delta` can be moved out of the loop, can't it?

```js
			// modify editable sections accordingly
			if (editableSections[change.to.line]) {
				var sections = editableSections[change.to.line];
				for (var i = 0; i < sections.length; i++) {
					// move any section start/end points that we are to the left of
				    var delta = change.text[0].length - (change.to.ch - change.from.ch);
					if (change.to.ch < sections[i][1]) {
						sections[i][1] += delta;
					}
					if (change.to.ch < sections[i][0]) {
						sections[i][0] += delta;
					}
				}
			}
```