remove duplicate dep

README.md

@@ -103,7 +103,7 @@ Hard drive space required: *roughly 2.5 GB*
              libslv2-dev dssi-utils vco-plugins wah-plugins fil-plugins \
              mda-lv2 libmp3lame-dev libspeex-dev libgsl0-dev \
              portaudio19-dev python-dev libsmpeg0 libjpeg62 flite1-dev \
-             libgsm1-dev libfftw3-dev libgtk2.0-dev git libstk0-dev \
+             libgsm1-dev libgtk2.0-dev git libstk0-dev \
              libsndobj-dev libfluidsynth-dev fluid-soundfont-gm byacc
 
 2. Clone the Purr-Data repository *(10 minutes)*