Remove redundant variable assignment in connection check

[Copilot]

Addressed code review feedback to simplify connection checking logic in __init__.py.

Changes:

• Removed intermediate is_connected variable that was only used once
• Directly evaluate await lock.async_internal_is_connection_up() in if statement

Before:

is_connected = await lock.async_internal_is_connection_up()
if not is_connected:
    _LOGGER.debug(...)

After:

if not await lock.async_internal_is_connection_up():
    _LOGGER.debug(...)

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