tdf#126597 don't use modeless dialog for senddoc.exe

There is already a large comment in initAttachmentList about
problems with MAPI_DIALOG_MODELESS. Using MAPI_DIALOG_MODELESS with
Outlook 2016 and multiple attachments sometimes produces a
MAPI_E_FAILURE, but most times it crashes for me. And it's not a
problem with the removed temporary files, as uncommenting that
shows the same problem. And there seems to be many more problems:

https://social.msdn.microsoft.com/Forums/en-US/5d8fece6-9d93-490c-9331-625c17e3291d/mapisendmailhelper-and-mapidialogmodeless

But actually I don't see any blocking of LO, if I switch to
using MAPI_DIALOG, as senddoc.exe already runs in the background.

So this switches MAPI_DIALOG_MODELESS to MAPI_DIALOG.

This reverts commit 5874c76371
("tdf#116074: Use modeless dialogs with supporting mailers").

Change-Id: Ie0f8f22196d1a174dfeada2bc4aabb1717ee16a7
Reviewed-on: https://gerrit.libreoffice.org/76155
Tested-by: Jenkins
Reviewed-by: Jan-Marek Glogowski <glogow@fbihome.de>

shell/source/win32/simplemail/senddoc.cxx

@@ -207,8 +207,9 @@ static void initParameter(int argc, wchar_t* argv[])
 
         if (_wcsicmp(argv[i], L"--mapi-dialog") == 0)
         {
-            // Outlook 2013+; for earlier versions this equals to MAPI_DIALOG
-            gMapiFlags |= MAPI_DIALOG_MODELESS;
+            // MAPI_DIALOG_MODELESS has many problems and crashes Outlook 2016.
+            // see the commit message for a lengthy description.
+            gMapiFlags |= MAPI_DIALOG;
         }
         else if (_wcsicmp(argv[i], L"--mapi-logon-ui") == 0)
         {