Refactor: Use `$#` to check parameters

diff --git a/git-open b/git-open
index da3561ebe52e041c81df8d5b8ba54387e0ec73a3..743707ca70086f6691b0e1c1be96285675cfd65a 100755 (executable)
--- a/git-open
+++ b/git-open
@@ -1,6 +1,6 @@
 #! /bin/sh
 
-if [ -z "$1" -o -n "$2" ]; then
+if [ $# -ne 1 ]; then
    echo "Usage: git open url_key" >&2
    exit 1
 else