Revert "Bug 544606 - Disabled button text not visible in dark theme on Mac"

It affects the text color of enabled Buttons in Forms.

This reverts commit 94519cab94d972759c797b69d211b623fc8d7808.

Change-Id: I7649a02c3b9f227086a0def7363ee29d00f749f1
diff --git a/bundles/org.eclipse.ui.themes/css/e4-dark_mac.css b/bundles/org.eclipse.ui.themes/css/e4-dark_mac.css
index 6d48d2c..7aa077d 100644
--- a/bundles/org.eclipse.ui.themes/css/e4-dark_mac.css
+++ b/bundles/org.eclipse.ui.themes/css/e4-dark_mac.css
@@ -202,6 +202,5 @@
 .MPart LayoutComposite > * > LayoutComposite > Section > LayoutComposite > Button,
 .MPartStack.active .MPart LayoutComposite > * > LayoutComposite > Section > LayoutComposite > Button {
     background-color: unset;
-    color: unset;
 }