contrib: samplerate has config.* in a custom dir

(cherry picked from commit ccf99a62de0e94ea8f6497a9688b7e5cc22d0be3)
Signed-off-by: Jean-Baptiste Kempf <jb@videolan.org>

contrib/src/samplerate/rules.mak

@@ -14,7 +14,7 @@ $(TARBALLS)/libsamplerate-$(SAMPLERATE_VERSION).tar.gz:
 
 samplerate: libsamplerate-$(SAMPLERATE_VERSION).tar.gz .sum-samplerate
 	$(UNPACK)
-	$(UPDATE_AUTOCONFIG)
+	$(UPDATE_AUTOCONFIG) && cd $(UNPACK_DIR) && mv config.guess config.sub Cfg
 	$(MOVE)
 
 .samplerate: samplerate