Update README.md

[hassanctech]

Issue #, if available:. https://github.com/awslabs/amazon-kinesis-video-streams-webrtc-sdk-c/issues/1567

Description of changes:

Remove , from readme to make properly formed JSON. It is correct here already: https://github.com/awslabs/amazon-kinesis-video-streams-webrtc-sdk-c/blob/master/scripts/generate-iot-credential.sh#L39-L56

By submitting this pull request, I confirm that you can use, modify, copy, and redistribute this contribution, under the terms of your choice.

[codecov-commenter]

Codecov Report

Base: 51.30% // Head: 51.31% // Increases project coverage by +0.00% :tada:

Coverage data is based on head (4a59f3c) compared to base (ced19d0). Patch has no changes to coverable lines.

:exclamation: Current head 4a59f3c differs from pull request most recent head 59805e5. Consider uploading reports for the commit 59805e5 to get more accurate results

Additional details and impacted files

@@           Coverage Diff           @@
##           master    #1568   +/-   ##
=======================================
  Coverage   51.30%   51.31%           
=======================================
  Files          46       46           
  Lines       12822    12820    -2     
=======================================
  Hits         6578     6578           
+ Misses       6244     6242    -2     

Impacted Files	Coverage Δ
samples/kvsWebRTCClientMaster.c	0.00% <0.00%> (ø)
samples/kvsWebRTCClientViewer.c	0.00% <0.00%> (ø)

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[sirknightj]

Closing in favor of #1637