added libfftw3-detection

git-svn-id: https://lmms.svn.sf.net/svnroot/lmms/trunk/lmms@1154 0778d3d1-df1d-0410-868b-ea421aaaa00d

plugins/Makefile.am

@@ -14,6 +14,10 @@ if FLUIDSYNTH_SUPPORT
 SF2PLAYER_DIR=sf2_player
 endif
 
+if HAVE_LIBFFTW3
+SPECTRUMANALYZER_DIR=spectrum_analyzer
+endif
+
 SUBDIRS =			\
 	audio_file_processor	\
 	bass_booster		\
@@ -30,7 +34,7 @@ SUBDIRS =			\
 	peak_controller_effect	\
 	$(SF2PLAYER_DIR)	\
 	$(SINGERBOT_DIR)	\
-	spectrum_analyzer	\
+	$(SPECTRUMANALYZER_DIR)	\
 	stereo_enhancer		\
 	stereo_matrix		\
 	$(STK_DIR)		\