hwpfilter: MSVC: pragma warning: make more specific, remove obsolete

Change-Id: I30b53bd7c5105fee6b384441bb2d996b2e216b21
Reviewed-on: https://gerrit.libreoffice.org/48981Tested-by: Jenkins <ci@libreoffice.org>
Reviewed-by: Mike Kaganski <mike.kaganski@collabora.com>

hwpfilter/source/precompile.h

@@ -18,15 +18,9 @@
  */
 
 #ifdef _WIN32
-    #if defined _MSC_VER
-        #pragma warning(push, 1)
-    #endif
     #define WIN32_LEAN_AND_MEAN
     #include <windows.h>
     #include <crtdbg.h>
-    #if defined _MSC_VER
-        #pragma warning(pop)
-    #endif
 #endif
 
 /* vim:set shiftwidth=4 softtabstop=4 expandtab: */