golang/oauth2: retrieve token before setting ticker to avoid initial delay

[encyphered]

This patch modifies the DeviceAccessToken function to avoid
an unnecessary delay before the first token request is made.

Previously, the function waited for the first interval duration
before making the initial call to retrieveToken. This behavior
causes delay.

This change introduces an immediate initial call to retrieveToken
before entering the ticker loop. Subsequent polling continues to honor
the server-specified interval, as expected.

[gopherbot]

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[gopherbot]

Message from Gopher Robot:

Patch Set 1:

(1 comment)

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[gopherbot]

Message from Gopher Robot:

Patch Set 1:

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[gopherbot]

Message from Sean Liao:

Patch Set 3:

(2 comments)

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