setup/source: allow user to remove one skipped dir

lib/setup/setupSource

@@ -35,6 +35,7 @@ setupSource() {
         This prompt will loop until an empty string is encountered.
 	EODesc
 	cd "$sourcepath"
+	count=${#skippeddirectories[@]}
 	for (( i=0 ; 1 ; i++ ))
 	do
 		read							\
@@ -45,9 +46,13 @@ setupSource() {
 		if [ -n "$value" ]
 		then
 			skippeddirectories[i]="$value"
+		elif (( i < count ))
+		then
+			unset skippeddirectories[i]
 		else
 			break
 		fi
 	done
+	unset count
 	cd - >/dev/null
 }