Fix .xltx file extension in Template import dialog

Change-Id: Ib7cb462720d13c31f0946a9c8b721d05ce7c9dfe
Reviewed-on: https://gerrit.libreoffice.org/55267Tested-by: Jenkins <ci@libreoffice.org>
Reviewed-by: Katarina Behrens <Katarina.Behrens@cib.de>

sfx2/source/doc/templatedlg.cxx

@@ -911,7 +911,7 @@ void SfxTemplateManagerDlg::OnTemplateImportCategory(const OUString& sCategory)
         if ( !sFilterExt.isEmpty() )
             sFilterExt += ";";
 
-        sFilterExt += "*.ots;*.stc;*xltx;*.xlt";
+        sFilterExt += "*.ots;*.stc;*.xltx;*.xlt";
     }
 
     if ( aModuleOpt.IsModuleInstalled( SvtModuleOptions::EModule::IMPRESS ) )