LibGUI: Make StatusBar 2px shorter vertically for a snugger fit

Libraries/LibGUI/StatusBar.cpp

@@ -37,7 +37,7 @@ namespace GUI {
 StatusBar::StatusBar(int label_count)
 {
     set_size_policy(SizePolicy::Fill, SizePolicy::Fixed);
-    set_preferred_size(0, 20);
+    set_preferred_size(0, 18);
     set_layout<HorizontalBoxLayout>();
     layout()->set_margins({ 0, 0, 0, 0 });
     layout()->set_spacing(2);