conan: MSVC runtime settings ignored by FLTK

CMakeLists.txt

cmake_minimum_required (VERSION 3.9.6)
project(testapp)

find_package(fltk REQUIRED)

add_executable(testapp test.cpp)
target_link_libraries(testapp fltk::fltk)

conanfile.txt

[requires]
fltk/1.3.9

[generators]
CMakeDeps
CMakeToolchain

test.cpp

#include <FL/Fl.H>              /* FLTK main       FLTK  */
#include <FL/Fl_Window.H>       /* FLTK window     FLTK  */
#include <FL/Fl_Button.H>       /* FLTK button     FLTK  */

#include <stdio.h>              /* I/O lib         ISOC  */
#include <stdlib.h>             /* Standard Lib    ISOC  */

////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
static void daButCall(Fl_Widget *w, void *uData)
{
  printf("The button was pressed\n");
}

////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
int main()
{
  Fl_Window win(500, 70, "Simple Button Demo Program");
  Fl_Button but(20, 20, 460, 30, "Test Button");
  but.callback(daButCall, (void *)0);
  win.show();
  return Fl::run();
}