Do not symlink a symlink in mkrc

We have a bug when calling mkrc(1) on a symlink:

```sh
mkrc ~/.vimrc # links ~/.vimrc to ~/.dotfiles/vimrc
mkrc ~/.vimrc # deletes ~/.dotfiles/vimrc
```

This catches that case ahead of time, preventing the user from running
mkrc(1) on a symlink.

Fix #144.

1 files changed, 0 insertions, 4 deletions

diff --git a/bin/rcup.in b/bin/rcup.in
index 910e534..78f5faa 100755
--- a/bin/rcup.in
+++ b/bin/rcup.in
@@ -121,10 +121,6 @@ replace_file() {
   link_file "$src" "$dest" "$sigil"
 }
 
-is_nested() {
-  echo "$1" | sed "s:$DEST_DIR/::" | grep '/' >/dev/null
-}
-
 is_identical() {
   diff -c "$1" "$2" > /dev/null 2>&1
 }