Recognize LOG_DAEMON as a valid facility

Index: src/config.c
--- src/config.c.orig
+++ src/config.c
@@ -67,6 +67,7 @@ configEnum maxmemory_policy_enum[] = {
     {NULL, 0}};
 
 configEnum syslog_facility_enum[] = {
+    {"daemon",  LOG_DAEMON},
     {"user", LOG_USER},
     {"local0", LOG_LOCAL0},
     {"local1", LOG_LOCAL1},
