android: remove redundant header causing build failure.

Change-Id: I857224b551ff6e5959ffe31e872ec4e4993bc174
Reviewed-on: https://gerrit.libreoffice.org/63343
Tested-by: Jenkins
Reviewed-by: Michael Meeks <michael.meeks@collabora.com>

vcl/headless/CustomWidgetDraw.cxx

@@ -10,7 +10,6 @@
 
 #include <cairo.h>
 #include <headless/CustomWidgetDraw.hxx>
-#include <sal/main.h>
 #include <sal/config.h>
 #include <rtl/bootstrap.hxx>
 #include <tools/svlibrary.h>