Fix missing NLS for "Enable theming" eclipse-platform#2480

The NLS for "Enable theming" is not found because of a recent change to
the according messages.properties file. This change reverts the faulty
change.

Fixes eclipse-platform#2480

Author: HeikoKlare

bundles/org.eclipse.ui.workbench/Eclipse UI/org/eclipse/ui/internal/messages.properties

@@ -496,7 +496,7 @@ OpenPerspectiveDialogAction_tooltip=Open Perspective
 
 #---- General Preferences----
 PreferencePage_noDescription = (No description available)
-PreferencePageParameterValues_pageLabelSeparator = \ >\
+PreferencePageParameterValues_pageLabelSeparator = \ >\ 
 ThemingEnabled = E&nable theming
 ThemeChangeWarningText = Restart for the theme changes to take full effect
 ThemeChangeWarningTitle = Theme Changed