Expliticly link with -lpthread if smbd is compiled with
avahi support. Otherwise the binary will fail to run.

Signed-off-by: Sven Neumann <s.neumann@raumfeld.com>
--- samba-3.6.24-orig/source3/Makefile.in	2014-06-23 18:41:30.903798176 -0700
+++ samba-3.6.24/source3/Makefile.in	2014-06-23 18:42:36.005454989 -0700
@@ -1783,7 +1783,7 @@
 		$(KRB5LIBS) $(DYNEXP) $(PRINT_LIBS) $(AUTH_LIBS) \
 		$(ACL_LIBS) $(PASSDB_LIBS) $(LIBS) $(DNSSD_LIBS) $(AVAHI_LIBS) \
 		$(POPT_LIBS) @SMBD_LIBS@ $(LIBTALLOC_LIBS) $(LIBTEVENT_LIBS) $(LIBTDB_LIBS) \
-		$(LIBWBCLIENT_LIBS) $(ZLIB_LIBS)
+		$(LIBWBCLIENT_LIBS) $(ZLIB_LIBS) $(PTHREAD_LDFLAGS)
 
 bin/nmbd@EXEEXT@: $(BINARY_PREREQS) $(NMBD_OBJ) @BUILD_POPT@ $(LIBTALLOC) $(LIBTEVENT) $(LIBTDB) $(LIBWBCLIENT)
 	@echo Linking $@