tags: use NULL in reads from db

lib/tags/update

@@ -52,12 +52,12 @@ echo '
 ;
 
 		SELECT "AtOM:NoMoreFiles";' >&3
-	read -u4 line
+	read -u4 -d$'\0' line
 	while ! [[ $line = AtOM:NoMoreFiles ]]
 	do
 		tagfiles+=("$line")
 		(( filecount++ ))
-		read -u4 line
+		read -u4 -d$'\0' line
 	done
 	echo 'BEGIN TRANSACTION;' >&3
 	for line in "${tagfiles[@]}"