ServicesList: Update Slack js_unread to avoid jQuery.

Fixes #96.

app/store/ServicesList.js

@@ -38,7 +38,7 @@ Ext.define('Rambox.store.ServicesList', {
 			,description: locale['services[1]']
 			,url: 'https://___.slack.com/'
 			,type: 'messaging'
-			,js_unread: `let checkUnread=()=>{const indirect=$(".p-channel_sidebar__channel--unread:not(.p-channel_sidebar__channel--muted)").length;let direct=0;$(".p-channel_sidebar__badge").each(function(){direct+=isNaN(parseInt($(this).html()))?0:parseInt($(this).html())}),rambox.updateBadge(direct,indirect)};setInterval(checkUnread,3e3);`
+			,js_unread: `let checkUnread=()=>{const indirect=document.querySelectorAll(".p-channel_sidebar__channel--unread:not(.p-channel_sidebar__channel--muted)").length;let direct=0,badges=document.getElementsByClassName("p-channel_sidebar__badge");for(const badge of badges){const i=parseInt(badge.innerHTML);direct+=isNaN(i)?0:i}rambox.updateBadge(direct,indirect)};setInterval(checkUnread,3e3);`
 		},
 		{
 			 id: 'noysi'