fix(script): Configure all switches in the loop

[CommitToday]

The configuration logic was incorrectly indented outside the main loop, which resulted in only the last switch being configured.

This commit moves the configuration commands inside the loop to ensure each switch is configured sequentially. It also updates the script to Python 3, adds basic error handling for the Telnet connection, and includes a command to save the running configuration.

Fixes #14

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Closes #14