printPublicIp: remove .sh

diff --git a/printPublicIp b/printPublicIp
new file mode 100755 (executable)
index 0000000..8938f6c
--- /dev/null
+++ b/printPublicIp
@@ -0,0 +1,3 @@
+#!/bin/sh
+
+curl www.sthu.org/whatismyip.html