improve performance when modifying text

src/Widget.cpp

@@ -22,9 +22,9 @@ void Widget::fit_text(std::string &text) {
         return;
 
     auto size = window()->painter().compute_text_size(rect(), text, style()->font_description());
-    // always reflow, even if resize doesn't
+    // always repaint, even if resize doesn't reflow
     if (!resize(size)) {
-        reflow();
+        repaint();
     }
 }