Update NWjs to 0.64

Author: haslinghuis

src/css/dark-theme.css

@@ -518,11 +518,6 @@ progress[value]::-webkit-progress-bar {
     border-bottom: 1px solid red;
 }
 
-/* .tab-osd .preview {
-    background: linear-gradient(rgba(0, 0, 0, 0.2), rgba(0, 0, 0, 0.2)), url(../images/osd-bg-1.jpg);
-    background-size: cover;
-} */
-
 .tab-osd .preview:active {
     background: linear-gradient(rgba(0, 0, 0, 0.2), rgba(0, 0, 0, 0.2)), url(../../images/osd-bg-1-grid.png), url(../../images/osd-bg-1.jpg);
     background-size: cover;