Fix incorrect handling of the "-" character on 7x4 segments

Author: wkuranowski

adafruit_ht16k33/segments.py

@@ -158,6 +158,7 @@
     0x40,  # -
     0x6E,  # y
     0x40,  # -
+    0x40,  # -
 )
 
 
@@ -461,7 +462,7 @@ def _put(self, char: str, index: int = 0) -> None:
         if char in "abcdefghijklmnopqrstuvwxy":
             character = ord(char) - 97 + 10
         elif char == "-":
-            character = 16
+            character = 36
         elif char in "0123456789":
             character = ord(char) - 48
         elif char == " ":