Use value attr for textarea

Because setting content as child text node seems to confuse Mithril. I
suspect that's because it uses 'value' property to get/set textarea
content.

client/long-text-component.js

@@ -15,21 +15,16 @@ const component = {
         title: text,
         onclick: () => {
           overlay.open(() => {
-            return m(
+            return m("textarea.long-text", {
-              "textarea.long-text",
+              value: text,
-              {
               cols: 80,
               rows: 24,
               readonly: "",
               oncreate: vnode2 => {
-                  setTimeout(() => {
                 vnode2.dom.focus();
                 vnode2.dom.select();
-                  }, 50);
               }
-              },
+            });
-              text
-            );
           });
         }
       },