[#2720] Check if /proc/sys/net/core/somaxconn exists before try to parse it
[#2720] Check if /proc/sys/net/core/somaxconn exists before try to parse it

Motivation:

As /proc/sys/net/core/somaxconn does not exists on non-linux platforms you see a noisy stacktrace when debug level is enabled while the static method of NetUtil is executed.

Modifications:

Check if the file exists before try to parse it.

Result:

Less noisy logging on non-linux platforms.

purplefox/netty-4.0.2.8-hacked,imangry/netty-zh,chanakaudaya/netty,chanakaudaya/netty,yipen9/netty,imangry/netty-zh,purplefox/netty-4.0.2.8-hacked,imangry/netty-zh,DavidAlphaFox/netty,yipen9/netty,purplefox/netty-4.0.2.8-hacked,imangry/netty-zh,chanakaudaya/netty,chanakaudaya/netty,DavidAlphaFox/netty,purplefox/netty-4.0.2.8-hacked,yipen9/netty,yipen9/netty,DavidAlphaFox/netty,chanakaudaya/netty,DavidAlphaFox/netty,imangry/netty-zh