try workaround for Python 3.7: must use () for assignments

src/extract_otp_secrets.py

@@ -91,17 +91,17 @@ Exception: {e}""")
     FONT_THICKNESS: Final[int] = 1
     FONT_LINE_STYLE: Final[int] = cv2.LINE_AA
     RECT_THICKNESS: Final[int] = 5
-    # PYTHON <= 3.7: do not use Types in Final
+    # PYTHON <= 3.7: must use () for assignments
     # START_POS_TEXT: Final[Point] = 5, 20
     # NORMAL_COLOR: Final[ColorBGR] = 255, 0, 255
     # SUCCESS_COLOR: Final[ColorBGR] = 0, 255, 0
     # FAILURE_COLOR: Final[ColorBGR] = 0, 0, 255
     # FONT_DY: Final[Tuple[int, int]] = 0, cv2.getTextSize("M", FONT, FONT_SCALE, FONT_THICKNESS)[0][1] + 5
-    START_POS_TEXT: Tuple[int, int] = 5, 20
-    NORMAL_COLOR: Tuple[int, int, int] = 255, 0, 255
-    SUCCESS_COLOR: Tuple[int, int, int] = 0, 255, 0
-    FAILURE_COLOR: Tuple[int, int, int] = 0, 0, 255
-    FONT_DY: Tuple[int, int] = 0, cv2.getTextSize("M", FONT, FONT_SCALE, FONT_THICKNESS)[0][1] + 5
+    START_POS_TEXT: Final[Tuple[Point]] = (5, 20)
+    NORMAL_COLOR: Final[Tuple[ColorBGR]] = (255, 0, 255)
+    SUCCESS_COLOR: Final[Tuple[ColorBGR]] = (0, 255, 0)
+    FAILURE_COLOR: Final[Tuple[ColorBGR]] = (0, 0, 255)
+    FONT_DY: Final[Tuple[int, int]] = (0, cv2.getTextSize("M", FONT, FONT_SCALE, FONT_THICKNESS)[0][1] + 5)
 
     qreader_available = True
 except ImportError: