AWS Config looking for Endpoint variable when not approriate

[HenryGeorgist]

cc-dotnet-sdk/Usace.CC.Plugin/AWSConfig.cs

Line 37 in 69161b5

aws_endpoint = Utility.GetEnv(profileName + "_" + "S3_ENDPOINT"); // used when S3_MOCK is true

Line 37 should be moved into the block conditioned on the mock environment valuable. It shold not be searched for if mock is false.