Hyperlink dialog: Don't close if it's already open

Steps to reproduce:

1) Writer. Insert -> Hyperlink. Leave the dialog open.
2) Click into the writer document and type a link "http://google.de/", this
   will get converted to a hyperlink.
3) Now right-click on the hyperlink and choose "Edit Hyperlink" from the
   context menu. The Hyperlink dialog will close.

The Hyperlink dialog should stay open and not close, if you want to
edit the hyperlink.

This commit fixes this.

Change-Id: I125c12733790632008cad1a9fc2d13bf16487381

sw/source/uibase/shells/textsh1.cxx

@@ -808,7 +808,7 @@ void SwTextShell::Execute(SfxRequest &rReq)
         }
         break;
         case FN_EDIT_HYPERLINK:
-            GetView().GetViewFrame()->ToggleChildWindow(SID_HYPERLINK_DIALOG);
+            GetView().GetViewFrame()->SetChildWindow(SID_HYPERLINK_DIALOG, true);
         break;
         case FN_REMOVE_HYPERLINK:
         {