Fix preview on hover not working when Animated emotes options was disabled.

Fixes #1546

This change introduces a "window timer" that runs every 100ms that we
use to update the pixmap if necessary, since there is no signal for "let
me know when this image is done loading".

src/singletons/WindowManager.cpp

@@ -111,6 +111,12 @@ WindowManager::WindowManager()
     QObject::connect(this->saveTimer, &QTimer::timeout, [] {
         getApp()->windows->save();  //
     });
+
+    this->miscUpdateTimer_.start(100);
+
+    QObject::connect(&this->miscUpdateTimer_, &QTimer::timeout, [this] {
+        this->miscUpdate.invoke();  //
+    });
 }
 
 MessageElementFlags WindowManager::getWordFlags()