BUG/MINOR: sink: Set default connect/server timeout for implicit ring buffers

BUG/MINOR: sink: Set default connect/server timeout for implicit ring buffers

Ring buffers may be implicitly created from log declarations when "tcp@",
"tcp6@", "tcp4@" or "uxst@" prefixes are used. These ring buffers rely on
unconfigurable proxies. While connect and server timeouts should be defined for
explicit ring buffers, it is no possible for implicit ones. However, a default
value must be set and TICK_ETERNITY is not an acceptable one.

Thus, now "1s" is set for the connect timeout and "5s" is set for server one.

This patch may be backported as far as 2.4.