fix(cli): update bit.ly link to use GitHub link directly (#3782)

Updated http://bit.ly link to link to GitHub directly so that it's clear where it leads and it is an `https` link.

Author: alsmola

packages/aws-cdk/test/integ/cli/test-cdk-iam-diff.sh

@@ -18,7 +18,7 @@ IAM Statement Changes
 ├───┼─────────────────┼────────┼────────────────┼────────────────────────────┼───────────┤
 │ + │ \${SomeRole.Arn} │ Allow  │ sts:AssumeRole │ Service:ec2.amazon.aws.com │           │
 └───┴─────────────────┴────────┴────────────────┴────────────────────────────┴───────────┘
-(NOTE: There may be security-related changes not in this list. See http://bit.ly/cdk-2EhF7Np)
+(NOTE: There may be security-related changes not in this list. See https://github.com/aws/aws-cdk/issues/1299)
 
 Resources
 [+] AWS::IAM::Role SomeRole SomeRole6DDC54DD