drawColon(false); turn off all dots instead of just the colon

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- Arduino board: **Uno**

- Arduino IDE version (found in Arduino -> About Arduino menu): **1.8.13**

- List the steps to reproduce the problem below (if possible attach a sketch or
copy the sketch code in too): **LIST REPRO STEPS BELOW**

Code (modifed from 'sevenseg' example):
#include // Enable this line if using Arduino Uno, Mega, etc.
#include
#include "Adafruit_LEDBackpack.h"

Adafruit_7segment matrix = Adafruit_7segment();

void setup() {
#ifndef __AVR_ATtiny85__
Serial.begin(9600);
Serial.println("7 Segment Backpack Test");
#endif
matrix.begin(0x70);
}

void loop() {

matrix.writeDigitRaw(2, 0x02);
matrix.writeDisplay();
delay(1000);
matrix.writeDigitRaw(2, 0x06);
matrix.writeDisplay();
delay(1000);
matrix.writeDigitRaw(2, 0x0e);
matrix.writeDisplay();
delay(1000);
matrix.writeDigitRaw(2, 0x1e);
matrix.writeDisplay();
delay(1000);
matrix.drawColon(false);
}

drawColon(false); not only turns off the colon, it turns off all the other dots as well

I looked at the library and believe the correct code is:
void Adafruit_7segment::drawColon(bool state) {
if (state)
displaybuffer[2] = displaybuffer[2] | 0x2;
else
displaybuffer[2] = displaybuffer[2] & 0xfd;
}

Search the Adafruit_7segment::drawColon(bool) implementation and reproduce the behavior with the modified sevenseg example on the Arduino Uno setup described. Done means drawColon(false) turns off only the colon while preserving the other dot segments; verify the display behavior with the example.

Written by the indexing model from the issue text.