fix: no need to proxy if IAM not initialized

[harshavardhana]

Description

fix: no need to proxy if IAM not initialized

Motivation and Context

IAM not initialized doesn't mean we can't still
read the content from the disk, we should just
allow the request to go-through if object layer
is initialized.

How to test this PR?

Need to manually block IAM loading and observe if requests
get re-routed unnecessarily

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Optimization (provides speedup with no functional changes)
• Breaking change (fix or feature that would cause existing functionality to change)

Checklist:

• Fixes a regression (If yes, please add commit-id or PR # here)
• Documentation updated
• Unit tests added/updated

[minio-trusted]

Mint Automation

Test	Result
mint-large-bucket.sh	✔️
mint-fs.sh	✔️
mint-gateway-s3.sh	✔️
mint-erasure.sh	✔️
mint-dist-erasure.sh	✔️
mint-zoned.sh	✔️
mint-gateway-nas.sh	✔️
mint-compress-encrypt-dist-erasure.sh	❌ more...

12416-8c9a8ef/mint-compress-encrypt-dist-erasure.sh.log:

Running with
SERVER_ENDPOINT:      minio-dev4.minio.io:30701
ACCESS_KEY:           minio
SECRET_KEY:           ***REDACTED***
ENABLE_HTTPS:         0
SERVER_REGION:        us-east-1
MINT_DATA_DIR:        /mint/data
MINT_MODE:            full
ENABLE_VIRTUAL_STYLE: 0

To get logs, run 'docker cp de38a15676b7:/mint/log /tmp/mint-logs'

(1/15) Running aws-sdk-go tests ... done in 1 seconds
(2/15) Running aws-sdk-java tests ... done in 2 seconds
(3/15) Running aws-sdk-php tests ... done in 43 seconds
(4/15) Running aws-sdk-ruby tests ... done in 3 seconds
(5/15) Running awscli tests ... done in 2 minutes and 12 seconds
(6/15) Running healthcheck tests ... done in 0 seconds
(7/15) Running mc tests ... done in 53 seconds
(8/15) Running minio-dotnet tests ... done in 50 seconds
(9/15) Running minio-go tests ... done in 2 minutes and 8 seconds
(10/15) Running minio-java tests ... FAILED in 1 minutes and 28 seconds
{
  "name": "minio-java",
  "function": "composeObject()",
  "args": "[single source with offset]",
  "duration": 65,
  "status": "FAIL",
  "error": "error occurred\nErrorResponse(code = InvalidArgument, message = Range specified is not valid for source object, bucketName = minio-java-test-2dp4t7f, objectName = minio-java-test-hns78i, resource = /minio-java-test-2dp4t7f/minio-java-test-hns78i, requestId = 1684842342BB72EE, hostId = 0f35ed24-c9e1-408b-a020-b5c3697ee806)\nrequest={method=PUT, url=http://minio-dev4.minio.io:30701/minio-java-test-2dp4t7f/minio-java-test-hns78i?uploadId=6053ed5d-cdc9-4ff9-92e4-44a5e6021c2a&partNumber=1, headers=x-amz-copy-source: /minio-java-test-2dp4t7f/minio-java-test-1jg10an\nx-amz-copy-source-range: bytes=2048-1048575\nx-amz-copy-source-if-match: cb92d17a904ccec2e6e23b8bb66245fb\nHost: minio-dev4.minio.io:30701\nAccept-Encoding: identity\nUser-Agent: MinIO (Linux; amd64) minio-java/8.0.3\nContent-MD5: 1B2M2Y8AsgTpgAmY7PhCfg==\nx-amz-content-sha256: e3b0c44298fc1c149afbf4c8996fb92427ae41e4649b934ca495991b7852b855\nx-amz-date: 20210601T170412Z\nAuthorization: AWS4-HMAC-SHA256 Credential=*REDACTED*/20210601/us-east-1/s3/aws4_request, SignedHeaders=content-md5;host;x-amz-content-sha256;x-amz-copy-source;x-amz-copy-source-if-match;x-amz-copy-source-range;x-amz-date, Signature=*REDACTED*\n}\nresponse={code=400, headers=Accept-Ranges: bytes\nContent-Length: 388\nContent-Security-Policy: block-all-mixed-content\nContent-Type: application/xml\nServer: MinIO\nVary: Origin\nX-Amz-Request-Id: 1684842342BB72EE\nX-Xss-Protection: 1; mode=block\nDate: Tue, 01 Jun 2021 17:04:12 GMT\n}\n >>> [io.minio.MinioClient.execute(MinioClient.java:775), io.minio.MinioClient.uploadPartCopy(MinioClient.java:4804), io.minio.MinioClient.composeObject(MinioClient.java:1431), FunctionalTest.testComposeObject(FunctionalTest.java:2120), FunctionalTest.composeObjectTests(FunctionalTest.java:2145), FunctionalTest.composeObject(FunctionalTest.java:2300), FunctionalTest.runObjectTests(FunctionalTest.java:3758), FunctionalTest.runTests(FunctionalTest.java:3783), FunctionalTest.main(FunctionalTest.java:3927)]"
}
(10/15) Running minio-js tests ... done in 51 seconds
(11/15) Running minio-py tests ... done in 2 minutes and 48 seconds
(12/15) Running s3cmd tests ... done in 18 seconds
(13/15) Running s3select tests ... done in 5 seconds
(14/15) Running security tests ... done in 0 seconds

Executed 14 out of 15 tests successfully.

Deleting image on docker hub
Deleting image locally

[poornas]

LGTM