Merge pull request ViennaRSS#14 from barijaona/vienna-issue1208

Fix problem : 
> When switching back to light mode, or when coming from the background
> some tabs seem grayed out. As soon as hovering with the mouse over them,
> they return to normal color.

MMTabBarView/MMTabBarView/MMTabBarView.m

@@ -362,7 +362,7 @@ - (void)windowStatusDidChange:(NSNotification *)notification {
 
     [self _updateImages];
 
-	[self setNeedsDisplay:YES];
+	[self setNeedsUpdate:YES];
 }
 
 #pragma mark -

MMTabBarView/MMTabBarView/Styles/Mojave Tab Style/MMMojaveTabStyle.m

@@ -235,10 +235,6 @@ - (void)drawBezelOfTabBarView:(MMTabBarView *)tabBarView inRect:(NSRect)rect
     // anything substantial. Instead, let's get the private iVar using this means:
     MMAttachedTabBarButton *addTabButton = [tabBarView valueForKey:@"_addTabButton"];
 
-    // If we don't invalidate the whole rect, then only the button will fill
-    // with the new color.
-    [tabBarView setNeedsDisplayInRect:rect];
-
     // In Mojave, during a mouse press there's also another highlighting; however MMTabBarView
     // doesn't provide the architecture that we need to implement this, but with the hack
     // above we can at least perform the hover behavior of Mojave.