Make sure that settings are written to config file when settings are removed.

Previously, settings where only written when a value has changed, and
removal of a setting value didn't count as a change.

src/settings.h

@@ -244,6 +244,8 @@ public:
 
 			updated[name] = true;
 		}
+		else //file contains a setting which is not in m_settings
+			value_changed=true;
 			
 		return true;
 	}