ncmpcpp: fix finding boost

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Signed-off-by: Sefa Eyeoglu <[e-mail]>

pkgs/by-name/nc/ncmpcpp/package.nix

···
     (lib.withFeature visualizerSupport "fftw")
     (lib.enableFeature clockSupport "clock")
     (lib.withFeature taglibSupport "taglib")
+    (lib.withFeatureAs true "boost" boost.dev)
   ];
 
   nativeBuildInputs = [