tdf#89329: use unique_ptr for pImpl in optinet2

Change-Id: I3f23ed564a10a9e6b0884fa1ad109d4d81ad1b6c
Reviewed-on: https://gerrit.libreoffice.org/25332
Reviewed-by: Noel Grandin <noelgrandin@gmail.com>
Tested-by: Noel Grandin <noelgrandin@gmail.com>

cui/source/options/optinet2.cxx

@@ -960,8 +960,7 @@ SvxEMailTabPage::~SvxEMailTabPage()
 
 void SvxEMailTabPage::dispose()
 {
-    delete pImpl;
-    pImpl = nullptr;
+    pImpl.reset();
     m_pMailContainer.clear();
     m_pMailerURLFI.clear();
     m_pMailerURLED.clear();

cui/source/options/optinet2.hxx

@@ -171,7 +171,7 @@ class SvxEMailTabPage : public SfxTabPage
 
     OUString      m_sDefaultFilterName;
 
-    SvxEMailTabPage_Impl* pImpl;
+    std::unique_ptr<SvxEMailTabPage_Impl> pImpl;
 
     DECL_LINK_TYPED(  FileDialogHdl_Impl, Button*, void );