Force-reload background image on config reload

Make it possible to see the change without restarting Mirage if an
image used for the theme's background was edited, or if used did the
mistake of typing "/path/to/img" then corrects it to
"file:///path/to/img".

TODO.md

@@ -1,7 +1,8 @@
 # TODO
 
+- handle invalid access token
+- If an account is gone from the user's config, discard UI state last page
 - room A-Z sorting
-- force reload theme ui background
 - move uiScale to settings.json
 - up/down doesn't work in the middle of a @word for which autocompletion isn't
   open because no matches
@@ -54,9 +55,6 @@
 
 - Catch server 5xx errors when sending message and retry 
 
-- Handle cases where a known account's access token is invalid
-- If an account is gone from the user's config, discard UI state last page
-
 - After forgetting a room, it comes back because of the "you left" event
 
 - `code`, mentions and links in quote ("> http://example.com") aren't properly

src/gui/UI.qml

@@ -32,7 +32,10 @@ Item {
     readonly property alias idleManager: idleManager
 
     function reloadSettings() {
-        py.loadSettings(() => { mainUI.pressAnimation.start() })
+        py.loadSettings(() => {
+            image.reload()
+            mainUI.pressAnimation.start()
+        })
     }