Revert "Under CentOS 5 the upstream git URL mist also not be HTTPS"

This reverts commit b41d10883a12f5057926714ac5d5fc4cb0b2a0b1.
Revert "Don't clone salt from HTTPS under CentOS-5"

This reverts commit 4809cc92a839624a8f5a6b96e438f8845330daa1.
Revert "Don't install from HTTPS in CentOS 5"

This reverts commit e39905fd839d07e3d7a953db4a9507769bd03d5e.
Revert "Also pass `--insecure` to `ez_setup.py`"

This reverts commit 544666faaf41ae99220041c0af61db6ac388cf70.
Revert "We can pass the `--insecure` directly"

This reverts commit 3ebc93b2b343c8e6e3c6e1de5beb10a1c65b44f8.