Update stripoutempties.js

In order to get the github html page maker to take the code entered here in ...innerHTML== ... which is supposed to be the HTML for an umbreaking space and produce a url usable in the bookmarklet instead of just printing to the page an unbreaking space, you need to html escape the percent then put in the number 26 which together make a url escaped ampersand, which then stops the github parser from converting your html code into the thing it encodes.