MEDIUM: checks: Implement redis check using tcp-check rules

A share tcp-check ruleset is now created to support redis checks. This way no
extra memory is used if several backends use a redis check.

The following sequence is used :

  tcp-check send "*1\r\n$4\r\nPING\r\n"

  tcp-check expect string "+PONG\r\n" error-status "L7STS" \
      on-error "%[check.payload(),cut_crlf]" on-success "Redis server is ok"
diff --git a/include/common/defaults.h b/include/common/defaults.h
index 43d287d..d52e005 100644
--- a/include/common/defaults.h
+++ b/include/common/defaults.h
@@ -179,7 +179,7 @@
 #define DEF_CHECK_PATH  ""
 #define DEF_SMTP_CHECK_REQ   "HELO localhost\r\n"
 #define DEF_LDAP_CHECK_REQ   "\x30\x0c\x02\x01\x01\x60\x07\x02\x01\x03\x04\x00\x80\x00"
-#define DEF_REDIS_CHECK_REQ  "*1\r\n$4\r\nPING\r\n"
+
 
 #define DEF_HANA_ONERR		HANA_ONERR_FAILCHK
 #define DEF_HANA_ERRLIMIT	10