[Qt] remove size grip to get rid of the right margin

IMO nobody needs a size grip and it looks bad

src/qt/bitcoingui.cpp

@@ -162,6 +162,9 @@ BitcoinGUI::BitcoinGUI(const NetworkStyle *networkStyle, QWidget *parent) :
 
     // Create status bar
     statusBar();
+    
+    // Disable size grip because it looks ugly and nobody needs it
+    statusBar()->setSizeGripEnabled(false);
 
     // Status bar notification icons
     QFrame *frameBlocks = new QFrame();