configure: make --windres option work

this option is described by --help, but the definition was missing in CMDLINE_SET.
7 years ago · 16ec62bbf4
--- a/configure
+++ b/configure
@@ -2436,6 +2436,7 @@ CMDLINE_SET="
    tempprefix
    toolchain
    valgrind
    windres
    x86asmexe
 "