better support for git worktree

transcrypt

@@ -656,7 +656,7 @@ save_configuration() {
 
 	# write the filter settings. Sorry for the horrific quote escaping below...
 	# shellcheck disable=SC2016
-	transcrypt_path='"$(git config transcrypt.crypt-dir 2>/dev/null || printf %s/crypt ""$(git rev-parse --git-dir)"")"/transcrypt'
+	transcrypt_path='"$(git config transcrypt.crypt-dir 2>/dev/null || printf %s/crypt ""$(git rev-parse --git-common-dir)"")"/transcrypt'
 
 	# Ensure filter attributes are always set for the default (unspecified) context
 	git config filter.crypt.clean "$transcrypt_path clean context=default %f"