Compiling on Fedora 36: <stdexcept> needed

[meilofveeningen-rl]

Compilation fails on Fedora 36 because is needed for std::runtime_error. The following patch fixes this:

diff --git a/include/ctbignum/gcd.hpp b/include/ctbignum/gcd.hpp
index 406d6d8..bdf97cd 100644
--- a/include/ctbignum/gcd.hpp
+++ b/include/ctbignum/gcd.hpp
@@ -19,6 +19,8 @@
 #include <ctbignum/utility.hpp>

 #include <cstddef>
+#include <stdexcept>
+

 namespace cbn {
 namespace detail {

[niekbouman]

Fixed in v0.6