Update twitpic.sh

cloudfront.net responds to either http or https requests.  For those versions of wget that do not support OpenSSL (BusyBox, etc.) I change the image download URL from https to http.

Tested using CM11 : 11-20140830-NIGHTLY-m7 (Android 4.4.4) | busybox v1.22.1 | Script Manager 2.9.6