Fixed issue #3760, handle X10 unit numbers greater than 9.

[mtl010957]

Description:
Added the colon to the string array index to slice all characters past the first one, to handle unit numbers that have more than one digit, any greater than 9.

Related issue (if applicable): fixes #3760

Pull request in home-assistant.io with documentation (if applicable): home-assistant/home-assistant.io#

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• Documentation added/updated in home-assistant.io

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[mention-bot]

@mtl010957, thanks for your PR! By analyzing the history of the files in this pull request, we identified @fotoetienne, @fabaff and @shmuelzon to be potential reviewers.

[fotoetienne]

👍 LGTM. Thanks for the bug fix!

[fotoetienne]

The tests seem to be failing for an unrelated reason. This patch looks good. Thanks, @mtl010957

[balloob]

🐬 top!