net: wifi: Update connect cmd to deal with new shell quoted args

Previously, the wifi shell needed to remove the quotes from the
SSID parameter, passed in by the underlying shell.

The new shell is now able to parse quoted strings as arguments,
so this adjustment can be removed.

Otherwise, it results in a failure to connect to an AP, as the first
character of the SSID name is stripped off.

Signed-off-by: Gil Pitney <gil.pitney@linaro.org>