tdf#138279 Revert "On double click on chart select the chart backgroud"

This reverts 7.1 commit 6a915073f8.

The change was simply wrong. There is NOTHING about this context
that indicates that a double-click is happening.

So whatever this patch was trying to do,
it simply was made in a completely wrong way.

So best to just revert, and put the onus back on the interested
parties to redesign a fix for their double-click issue.

Change-Id: Ia209c0552839d6cce1b348432789f0f861ac5703
Reviewed-on: https://gerrit.libreoffice.org/c/core/+/152023
Reviewed-by: Justin Luth <jluth@mail.com>
Tested-by: Jenkins

chart2/source/controller/sidebar/ChartLinePanel.cxx

@@ -55,10 +55,7 @@ OUString getCID(const rtl::Reference<::chart::ChartModel>& xModel)
 
     css::uno::Any aAny = xSelectionSupplier->getSelection();
     if (!aAny.hasValue())
-    {
+        return OUString();
-        xSelectionSupplier->select(css::uno::Any(OUString("CID/Page=")));
-        aAny = xSelectionSupplier->getSelection();
-    }
 
     OUString aCID;
     aAny >>= aCID;