Bump up the version number

lib/SCSI2SD/CHANGELOG

@@ -1,3 +1,6 @@
+20210508        6.4.4
+    - More bug fixes for firmware hanging during read/writes
+
 20210504        6.4.3
     - More bug fixes while writing data.
 

lib/SCSI2SD/src/firmware/config.c

@@ -36,7 +36,7 @@
 
 #include <string.h>
 
-static const uint16_t FIRMWARE_VERSION = 0x0643;
+static const uint16_t FIRMWARE_VERSION = 0x0644;
 
 // Optional static config
 extern uint8_t* __fixed_config;