Don't hide close button for chats

I find it useful to be able to close them

css/inverse.css

@@ -7665,8 +7665,6 @@ body {
     font-size: 50%;
     height: auto;
     line-height: 22px; }
-  #conversejs.fullscreen .chat-head.chat-head-chatbox .close-chatbox-button {
-    display: none; }
 #conversejs.fullscreen .chatbox {
   width: 100%;
   height: 100%;

sass/inverse/_chatbox.scss

@@ -17,11 +17,6 @@
             height: auto;
             line-height: $line-height;
         }
-        &.chat-head-chatbox {
-            .close-chatbox-button {
-                display: none;
-            }
-        }
     }
     .chatbox {
         width: 100%;

src/converse-chatview.js

@@ -263,10 +263,10 @@
                     if (!_converse.allow_contact_removal) { return; }
                     const result = confirm(__("Are you sure you want to remove this contact?"));
                     if (result === true) {
-                        this.contact.removeFromRoster(
+                        this.model.contact.removeFromRoster(
                             (iq) => {
-                                this.contact.destroy();
-                                delete this.contact;
+                                this.model.contact.destroy();
+                                delete this.model.contact;
                             },
                             (err) => {
                                 _converse.log(err, Strophe.LogLevel.ERROR);