Fix replace point widget.

In general problem here is that CWM need widget id in string, but
UI.ReplaceWidget need widget with sym, so we use to_sym for replace
point and then for method call.

library/cwm/src/lib/cwm/widget.rb

@@ -829,14 +829,14 @@ class ReplacePoint < CustomWidget
     # placeholder needed to be in dialog. Parameter type is limited by component
     # system
     # @param widget [CWM::AbstractWidget] initial widget in placeholder
-    def initialize(id: :_placeholder, widget: Empty.new(:_initial_placeholder))
+    def initialize(id: "_placeholder", widget: Empty.new("_initial_placeholder"))
       self.handle_all_events = true
       self.widget_id = id
       @widget = widget
     end
 
     def contents
-      ReplacePoint(Id(widget_id), widget_content(@widget))
+      ReplacePoint(Id(widget_id.to_sym), widget_content(@widget))
     end
 
     def init
@@ -848,7 +848,7 @@ def init
     # @param widget [CWM::AbstractWidget] widget to display and process events
     def replace(widget)
       log.info "replacing with new widget #{widget.inspect}"
-      Yast::UI.ReplaceWidget(@id, widget_content(widget))
+      Yast::UI.ReplaceWidget(widget_id.to_sym, widget_content(widget))
       @widget = widget
       init
     end