tidy up the code a bit.

git-crypt-unlock-all.sh

@@ -34,12 +34,12 @@ function verify_gpg_passphrase() {
 } 
 
 # MAIN
-if [ -z $1 ];
+keyfile=${1:-''}
+if [ -z $keyfile ];
 then
   verify_gpg_passphrase
   [ $foundkey -ne 0 ] && abort "Unable to decrypt."
 else
-  keyfile="$1"
   [ ! -f $keyfile ] && abort "unable to read $keyfile."
 fi