Do not compare SwContentIndex instances from different nodes

It fires an assert in dbgutil builds; and it doesn't make sense
anyway: we must use the index from the beginning, not a strange
minimal value between indices in start node and end node.

Change-Id: I4a2b6062f5524703737ca6029f428f30555d25b4
Reviewed-on: https://gerrit.libreoffice.org/c/core/+/157842
Tested-by: Jenkins
Reviewed-by: Mike Kaganski <mike.kaganski@collabora.com>
diff --git a/sw/source/uibase/shells/translatehelper.cxx b/sw/source/uibase/shells/translatehelper.cxx
index c62e4a59..64cd27e 100644
--- a/sw/source/uibase/shells/translatehelper.cxx
+++ b/sw/source/uibase/shells/translatehelper.cxx
@@ -178,7 +178,7 @@ void TranslateDocumentCancellable(SwWrtShell& rWrtSh, const TranslateAPIConfig& 
                else if (n == startNode)
                {
                    cursor->SetMark();
                    cursor->GetPoint()->nContent = std::min(aPoint.nContent, aMark.nContent);
                    cursor->GetPoint()->nContent = aPoint.nContent;
                }
                else if (n == endNode)
                {