dietpi-set_software: APT mirror: skip trailing slash for default Debian mirror

as we did in all other cases already: an alignment. The trailing slash is truncated internally anyway. We tend to add it for fully qualified URLs in other contexts to avoid a potential 301 redirect, but APT mirrors are never accessed like that, but only the (In)Release and Package(.*) files for the repo suite and component.

Author: MichaIng

dietpi/func/dietpi-set_software

@@ -318,7 +318,7 @@ $FP_SCRIPT	rpi_kernel_choice		<empty> Supported on Debian Bookworm or newer on R
 
 		# Debian
 		else
-			[[ $INPUT_MODE_VALUE == 'default' ]] && INPUT_MODE_VALUE='https://deb.debian.org/debian/'
+			[[ $INPUT_MODE_VALUE == 'default' ]] && INPUT_MODE_VALUE='https://deb.debian.org/debian'
 
 			G_EXEC eval "echo 'deb $INPUT_MODE_VALUE $G_DISTRO_NAME main contrib non-free non-free-firmware
 deb $INPUT_MODE_VALUE $G_DISTRO_NAME-updates main contrib non-free non-free-firmware