www/nyxt: fix build on powerpc64le and possibly others

On powerpc64le (optimize debug) removes some optimizations that
by default remove dead code. Here in particular that dead code is also
incorrect and it causes:
Unhandled UIOP/LISP-BUILD:COMPILE-FILE-ERROR in thread #<SB-THREAD:THREAD tid=612698 "main thread" RUNNING

                                                        {1001AB051C}>:
COMPILE-FILE-ERROR while compiling #<CL-SOURCE-FILE "idna" "decode">