Fixed WebInspector inability to early report errors

Fixed WebInspector inability to early report errors

This is a little bit hacky implementation of port check, because in some
conditions it may happen that port will be taken between the check and
initialization of WebInspector on proper thread. Unfortunetly sockets
can't be passed between threads. They strictly belong to the thread they
were created.

Bug: http://107.108.218.239/bugzilla/show_bug.cgi?id=9549
Reviewed by: Janusz Majnert, Piotr Tworek

Change-Id: Iadac46a3152f96e944a274fb1a9afedc6260f386
Signed-off-by: Kamil Klimek <k.klimek@partner.samsung.com>