Typo in the botocore repo URL in amazon-api output

[shapirus]

Running e.g. PERL5LIB=$(pwd)/local/lib/perl5 local/bin/amazon-api -m Route53 -s route53 -b botocore:

In order to create stubs or shapes you must clone the Botocore project
and provide the path to the project using the -b option or by setting
the environment variable BOTOCORE_PATH.

  git clone https:/github.com/boto/botocore.git /tmp/botocore

There's a single slash after https: instead of a double slash, which makes the URL invalid.