fixed repo URL

Author: siddacious

.gitmodules

@@ -471,4 +471,4 @@
 	url = https://github.com/adafruit/Adafruit_CircuitPython_BD3491FS.git
 [submodule "libraries/drivers/ds3502"]
 	path = libraries/drivers/ds3502
-	url = git@github.com:adafruit/Adafruit_CircuitPython_DS3502.git
+	url = https://github.com/adafruit/Adafruit_CircuitPython_DS3502.git