Fix bug in paredit-delete-forward and paredit-delete-backward
Fix bug in paredit-delete-forward and paredit-delete-backward

An error was thrown after forward deleting at end of line
and to backward deleting at beginning of line.

snmsts/lem,snmsts/lem,cxxxr/lem,cxxxr/lem,snmsts/lem,cxxxr/lem,cxxxr/lem,snmsts/lem