[Gtk-3.22] Normalize Switches. Fixes #396

Author: khurshid-alam

src/gtk-3.20/scss/widgets/_toggle.scss

@@ -105,12 +105,12 @@ $suffix: if($variant == "dark", "-dark", "");
 @include exports("switch") {
     switch {
         border-radius: $roundness;
-        padding: $spacing - 1px;
+        padding: $spacing - 2px;
         border: none;
         outline: none;
         transition: background-color .3s linear;
-        min-width: 88px;
-        min-height: 24px;
+        min-width: 48px;
+        min-height: 16px;
         background-color: $switch_bg_color;
         color: $switch_fg_color;
         box-shadow: inset 1px -1px 0 alpha($dark_shadow, .06), inset -1px 1px 0 alpha($dark_shadow, .06);