Correct libsamplerate version checking

git-svn-id: svn+ssh://jackaudio.org/trunk/jack@1104 0c269be4-1314-0410-8aa9-9f06e86f4224

drivers/netjack/Makefile.am

@@ -2,7 +2,7 @@ MAINTAINCLEANFILES = Makefile.in
 
 AM_CFLAGS = $(JACK_CFLAGS) 
 
-if HAVE_SNDFILE
+if HAVE_SAMPLERATE
 
 plugindir = $(ADDON_DIR)