BUG/MEDIUM: unix: failed abstract socket binding is retryable

Jan Seda noticed that abstract sockets are incompatible with soft reload,
because the new process cannot bind and immediately fails. This patch marks
the binding as retryable and not fatal so that the new process can try to
bind again after sending a signal to the old process.

Note that this fix is not enough to completely solve the problem, but it
is necessary. This patch should be backported to 1.5.
(cherry picked from commit 3c5efa2b3268f31cffc2c18887010d4bc906a066)
1 file changed