Recognize LOG_DAEMON as a valid facility

Index: src/config.c
--- src/config.c.orig
+++ src/config.c
@@ -56,6 +56,7 @@ configEnum maxmemory_policy_enum[] = {
 };
 
 configEnum syslog_facility_enum[] = {
+    {"daemon",  LOG_DAEMON},
     {"user",    LOG_USER},
     {"local0",  LOG_LOCAL0},
     {"local1",  LOG_LOCAL1},