default-octave: Rename configure variable (bug #62715). * src/default-octave.mk: The configure variable "ax_blas_integer_size" was renamed to "ax_cv_blas_integer_size" in Octave's build system. Adapt rule for that change.

#include <iostream>
#include <cpp/poppler-version.h>

int main(int argc, char *argv[])
{
    (void)argc;
    (void)argv;

    std::cout << "Poppler version: " << poppler::version_string() << std::endl;

    return 0;
}