Disconnect slave when pos is UNSAFE

Disconnect slave when pos is UNSAFE instead of sending an error that
stops the replication

server/modules/include/blr.h

@@ -180,6 +180,10 @@
 /* string len for master registration query  */
 #define BLRM_MASTER_REGITRATION_QUERY_LEN	255
 
+/* Read Binlog position states */
+#define SLAVE_POS_READ_OK			0x0
+#define SLAVE_POS_READ_ERR			0xff
+#define SLAVE_POS_READ_UNSAFE			0xfe
 /**
  * Some useful macros for examining the MySQL Response packets
  */