tdf#116404 RTF: check locale if BiDi inherits Environment

RTF is a bit simplistic compared to the others, but at least
we can handle the Environment situation similarly.

Change-Id: I87bc389373275d19f1229e11ffd742836a0fd498
Reviewed-on: https://gerrit.libreoffice.org/66966
Tested-by: Jenkins
Reviewed-by: Justin Luth <justin_luth@sil.org>

sw/source/filter/ww8/rtfattributeoutput.cxx

@@ -3490,7 +3490,11 @@ void RtfAttributeOutput::FormatFrameDirection(const SvxFrameDirectionItem& rDire
 {
     if (!m_rExport.m_bOutPageDescs)
     {
-        if (rDirection.GetValue() == SvxFrameDirection::Horizontal_RL_TB)
+        SvxFrameDirection nDir = rDirection.GetValue();
+        if (nDir == SvxFrameDirection::Environment)
+            nDir = GetExport().GetDefaultFrameDirection();
+
+        if (nDir == SvxFrameDirection::Horizontal_RL_TB)
             m_aStyles.append(OOO_STRING_SVTOOLS_RTF_RTLPAR);
         else
             m_aStyles.append(OOO_STRING_SVTOOLS_RTF_LTRPAR);