tests: httpextbin: update test case for unsupported protocol
tests: httpextbin: update test case for unsupported protocol

When given an unsupported protocol, error message will be posting
from bin. And configuring to bin has to be stop.

Change-Id: Idaafad6643a99f88efa72936b613ad14f3e7af52
Reviewed-on: https://gpro.palm.com/29984
Tested-by: HoonHee Lee <41497318ef67053f37c2ac0e974a3369f66d66ec@lge.com>
Reviewed-by: Jeongseok Kim <0c03ab7a1b32f29697716389c3f9549845834271@lge.com>
Tested-by: Jeongseok Kim <0c03ab7a1b32f29697716389c3f9549845834271@lge.com>

justinjoy/gst-plugins-lp,justinjoy/gst-plugins-lp