version macro increment, Release 2.5.9

Author: Daniel Shelepanov

src/pg_probackup.h

@@ -344,7 +344,7 @@ typedef enum ShowFormat
 #define BYTES_INVALID		(-1) /* file didn`t changed since previous backup, DELTA backup do not rely on it */
 #define FILE_NOT_FOUND		(-2) /* file disappeared during backup */
 #define BLOCKNUM_INVALID	(-1)
-#define PROGRAM_VERSION	"2.5.8"
+#define PROGRAM_VERSION	"2.5.9"
 
 /* update when remote agent API or behaviour changes */
 #define AGENT_PROTOCOL_VERSION 20501