Fix WhatsApp detection properly.

Ref: TheGoddessInari#261

app/store/ServicesList.js

@@ -28,7 +28,29 @@ Ext.define('Hamsket.store.ServicesList', {
 			,description: locale['services[0]']
 			,url: 'https://web.whatsapp.com/'
 			,type: 'messaging'
-			,js_unread: `let checkUnread=()=>{const elements=document.querySelectorAll("#pane-side ._23LrM");let count=0;for(const i of elements){const gp=i.parentNode.parentNode;0===gp.querySelectorAll('#pane-side *[data-icon="muted"]').length&&count++}hamsket.updateBadge(count)};setInterval(checkUnread,1e3);let unregister_queue=[];navigator.serviceWorker.getRegistrations().then(registrations=>{for(const registration of registrations)unregister_queue.push(registration.unregister());return unregister_queue}).then(queue=>{}).catch(err=>{});`
+			,js_unread: `
+			const className = Array.from(document.styleSheets)
+			  .flatMap(s => Array.from(s.cssRules))
+			  .filter(r => r instanceof CSSStyleRule)
+			  .find(({style}) => style.color === 'var(--unread-marker-text)')
+			  .selectorText.split('.').reverse()[0];
+			let checkUnread = () => {
+			  const elements = document.querySelectorAll("#pane-side ." + className);
+			  let count = 0;
+			  for (const i of elements) {
+				const gp = i.parentNode.parentNode;
+				0 === gp.querySelectorAll('#pane-side *[data-icon="muted"]').length && count++;
+			  }
+			  hamsket.updateBadge(count);
+			};
+			setInterval(checkUnread, 1e3);
+			let unregister_queue=[];
+			navigator.serviceWorker.getRegistrations().then(registrations => {
+			  for (const registration of registrations)
+				unregister_queue.push(registration.unregister());
+			  return unregister_queue;
+			}).then(queue => {}).catch(err => {});
+		  `
 		},
 		{
 			 id: 'slack'