stc15: print BSL minor version

The BSL version has the form X.Y.ZW in newer BSLs. The extra digit
is stored in another info packet byte. Print the version correctly.

stcgal/protocols.py

@@ -1654,7 +1654,9 @@ class Stc15Protocol(Stc15AProtocol):
         self.wakeup_freq, = struct.unpack(">H", packet[1:3])
 
         bl_version, bl_stepping = struct.unpack("BB", packet[17:19])
-        self.mcu_bsl_version = "%d.%d%s" % (bl_version >> 4, bl_version & 0x0f,
+        bl_minor = packet[22] & 0x0f
+        self.mcu_bsl_version = "%d.%d.%d%s" % (bl_version >> 4, bl_version & 0x0f,
+                                           bl_minor,
                                            chr(bl_stepping))
         self.bsl_version = bl_version