kup: fix build on musl

srcpkgs/kup/patches/musl.patch

@@ -0,0 +1,10 @@
+--- a/daemon/fsexecutor.cpp
++++ b/daemon/fsexecutor.cpp
+@@ -15,6 +15,7 @@
+ 
+ #include <fcntl.h>
+ #include <sys/stat.h>
++#include <sys/select.h>
+ 
+ namespace {
+