status label: replace hard-coded constant which doesn't work

Signed-off-by: Felix Paul Kühne <fkuehne@videolan.org>

Sources/VLCStatusLabel.m

@@ -104,7 +104,7 @@
 - (CGSize)sizeThatFits:(CGSize)size
 {
     CGSize textSize = [self.text sizeWithAttributes:self.font.fontDescriptor.fontAttributes];
-    textSize.width += 16.f; // take extra width into account for our custom drawing
+    textSize.width += size.height * 4.; // take extra width into account for our custom drawing
     return textSize;
 }